Online, free classifieds wiped out newspaper revenues by an average of 40% when CL took hold, after 2000 when CL spread to most major cities in the US. So, basically, you had one company of 50~ employees potentially wiping out the employment of probably tens of thousands (maybe 40K or so, according to some estimates).
Then you had the "legacy media" thing, still affecting newspapers. Going online doesn't really make all that much of a difference in their vitality, unfortunately, as -- according to Pew -- online readership has continuously dropped post-2016, and revenues aren't exactly keeping newspapers in the black. If online revenues were doing that, the LA Times wouldn't have been losing tens of millions of dollars every year and laid off 110~ employees last year.
Last year (2023) I think around 150 local newspapers folded in the US (2.5 papers a week, according to NPR), an increase from 2 per week that folded the previous year (2022). That's a fairly large increase of newspaper failures in just one yearr. 30% of newspapers in the US have folded since 2005 -- probably thanks to the WWW and the online, free classified ads effect. During the same time period (2005-2023) 48K journalists lost their jobs.
It's the internet/social media/TikTok-ing of journalism. In the mid 80s, there were an estimated 250K-350K journalists in the US, which at the time had 220 million people. Today, there are 46K journalists in the US (acc. to the BLS), and the population in the US has increased to probably over 330 million people.
Then again, the spread of podcasters, influencers, social media style "news" sites has spread. So really, I think we're seeing the redefinition of journalism. And internet, online newspaper operations -- which really are the only valid direction for newspapers to take -- so far aren't delivering on the promise of keeping newspaper operations alive and vital.