When I began in the early 2000s in Australia, it was really the last decade of the independent stations/small networks, before more of them where gobbled up by the large networks.
My first two paid gigs were actually at community radio stations, or as you'd say in the US, public access stations. Both were government funded positions, with the main duties being either station admin or PD, but I'd also fill in a lot on air. Colac (the first station) was a population of about 12,000 for the town (about 50,000 for the licence area), while Bordertown was about 2,000 for the town (around 15,000 for the licence area).
Then I jumped into commercial radio and headed out to Charleville, Queensland - 10 hours drive west of Brisbane, next nearest "town" a good hour away, population about 3,500 (about 7,500 for the licence area). It was part of the small, independent, radio group "Smart Radio Network" - a husband and wife ran small business. Traditional AM/FM combo - FM playing the 80s, 90s, 00s, while the AM played 60s-00s (the more recent music being on the softer side) and country, with a syndicated talk show in the 9am slot, and rural news at Midday. They even had some 1611 and 1629 AM stations (the "X Band" in Australia) that played a Hot Country format (and I did the breakfast show on in my second stint there). We had local announcers 6am-6pm each weekday.
I loved working in that station, as the owners would give staff the freedom to do whatever we wanted when it came to trying new ideas "as long as it pays for itself". I did two stints there, but would leave after a period of time (both times) as the pay was low and I would always get home sick for Melbourne (I'm a big city kid). For an American context, it would be like growing up in Brooklyn, then working in a tiny Arizona town.
Some other stations I had short stints at included Power FM on the New South Wales' South Coast - I quit there after a month, as the station had two towns it was based out of. I was meant to go to the bigger town, the beautiful Batesman's Bay, but at the last second the PD complained to the Manager that they wanted me where they were located, in the smaller Bega. It was also creatively frustrating, as we only had one production studio (with PC that was compatible with the on-air system for both stations) and when I came in after working hours so I could have some time in there to improvement some bits for my show, I got told off by the PD and was told not to come in outside working hours!
Someone else mentioned mining towns, well I worked Emerald, Queensland in 2008/2009, in the heart of coal mining country. I was the only live overnight shift in a small regional market anywhere in the country! Simply, the mining companies were paying the network big bucks to the fund the shift. Although it was an AM station (with FM repeaters in the mines) we were told to play "anything the miners want". This includes Metallica and Rage against the Machine (on AM!), and even the odd comedy song, like Adam Sandler's "Piece of sh*t car"! I was probably going to stick it out there a little while longer, with the aim to transfer to another station around the network, but then we (those on the AM side of our AM/FM combo) became 'divested'. In Australian media law, you're only allowed to own a certain amount of radio stations, TV stations and newspapers in any given market. The network sold to another network, which owned the TV station, which meant they had to sell the TV station or one of the AM/FM stations. When we (the AM side) were in the sale process, it meant we couldn't transfer to elsewhere in that network as it would be seen as devaluing the station (rules came in after it happened a few years before with another network).
Then I made the dumbest move of my career. Got an offer to work for a station in my home state, located just a three hour drive from where I grew up - great, I could visit home on the weekends, I thought. The pay was $10,000 less a year than the current gig, but I took the hit thinking "don't worry about the money, you'll be happy as you'll be closer to home". WRONG!
I was warned by another jock (who had worked there) that the SM, (Small) Network PD/MD and Group Manager were snakes, and he was 100% right. He also forgot to mention the incompetent part. I was on a station that was supposedly a rock format, but we were playing Madonna, Kylie Minogue, Taylor Swift, Katy Perry, Spice Girls - like, WTF?! How many times I got stopped down the street by listeners asking me "Why are you guys called [redacted] but play all the new girly pop?". It was so frustrating, especially since I loved that town, and it was close enough to home for me. In the end, management got sick of me pointing out everything they were doing wrong and tried to sack me. Breach of contract, lawyers at ten paces, eventual financial settlement.
It was my last full-time paid on-air gig. I stayed in the industry for another 8 years, working off-air in the production side of things, with the occasional freelance news reading gig. Now, I dabble in it as a volunteer doing my first passion, sports broadcasting. That said, the radio bug is starting to bite again, so I'm starting to build up a couple of internet stations, just as a hobby.
To the OP's original point of a back-up plan.
By luck, working in the railways had been in the family. My father worked on the track gang, my step-father was an Assistant Station Master, and my uncle volunteered at the railway museum.
I ended up joining the railways in the passenger services section about 7 years ago, and although there's the occasional grumble like any job, I love it. A lot of the skills in radio are transferrable to the job, including announcing trains and passing on relevant information (delays, etc). Even setting up for bus replacements almost feels like setting up for an OB!
The best part (despite the shift work) is that it's a good union paying job. I earn at least double than what I would be getting if I worked in radio now, even close to triple from what that last full-time on-air job paid. The railways are also one of those jobs that unless you seriously screw-up, it's a job for life (if you want it to be). The ability to take some nice (and long) holidays, which I wasn't able to in radio, is another benefit.
As a side bar, a few years ago on an Australian radio Facebook group, there was a PD at station (that I had previously worked at) complaining how they couldn't find anyone decent to fill the 6am to 10am slot, and how anyone decent didn't want to move to a regional town to earn their stripes.
I commented in reply "Why would they? To move away from the big city, to a small town, with no friends, no budget for their show to do cool stuff, and do it all on sh*t pay? Years ago, you had no choice. To be a star, you had to do that. Now, with YouTube, Twitch, Instagram and TikTok, people can become a certain level of famous and earn a wage from it, and do it from anywhere they want to in the world".