All due respect, then, it's very hard to have an intelligent discussion about this topic without a firm grounding in the BBC's unique history and all the remarkable services it provides, in ways that are completely alien to anyone who's only experienced American commercial broadcasting and our very limited public broadcasting system.
There's a 100-year legacy of public service there that long predates any sort of commercial broadcasting in the UK. There was no commercial television until 1955, and no domestic commercial radio until the early 1970s. Turning the BBC into an advertising-driven service would so radically change its nature as to be unrecognizable.
I'd very strongly encourage you to spend some time reading up on the BBC's history and listening to some of its many offerings, especially on the radio side. Radio 1 has the explicit remit to serve younger listeners and to keep changing as new generations of listeners move into its demographic. Its offshoot 1Xtra is specifically aimed at minority audiences. Radio 2 is one of the most remarkable AC-flavo(u)red broadcast services in the world. Radio 3 is simply the finest cultural radio service on the globe. Radio 4 provides all sorts of spoken-word programming that has only the faintest equivalent here - there's radio drama and comedy that does not exist anywhere here, and would not find commercial advertiser support if they tried. (Just one tiny example: we wouldn't have Hitchhiker's Guide to the Galaxy if it hadn't started as a Radio 4 experiment.) There are also panel shows that are brilliant and often hilarious (that's where we copied Wait, Wait Don't Tell Me! from), public affairs, poetry, literary talk, religious discussions, a radio soap opera (The Archers) that has been running for longer than we've been alive, and on and on and on. Radio 4 alone supports an incredible ecosystem of British writers, producers, content creators, talent and other audio artists who'd never be able to do the things they do without the BBC. (Entire books have been written about the unique entity that is Radio 4.) Radio 5 Live is a more traditional news/talk/sports service of a type we'd recognize here. Then there are 6Music and several other more niche digital services that program more specific music and talk formats, none of which are duplicated in the commercial world.
And all of those are just the main national services. There's BBC local radio that provides important news and information for communities all over Britain, there are national services that are the only national radio services to Wales, Scotland and Northern Ireland, there are language services in Welsh and Scottish Gaelic, there's the BBC South Asian service that provides an important service to immigrant communities in the Midlands, and that's just the linear radio offerings.
It's an amazing institution, and while it certainly has its issues and problems, pulling the plug on its funding source is a political ploy, not an answer. What the Tories are proposing is an act of cultural vandalism. It deserves plenty of discussion - but only in the context of a better understanding of what the BBC has been, still is, and is in the process of becoming.