Yeah the laws changed a few years ago so the only catchup you need a license for is BBC content(But weirdly you can still get the two thirds off the price if you have a black and white TV). The fee is to fund the BBC because they don't have any adverts, having a non-commercial income ensures there's no conflicts of interest commercial or product placement(Which is super strictly regulated in UK compared to rest of world), and that they can reliably offer a lot of general public services that wouldn't be in the interests of commercial companies to offer, besides entertainment content though which tbf they turn out a pretty wide variety of content for the budget they run on.
However, at this point it should just be funded by general taxation, it's the only way forward that both maintains the necessary public services, a commercially independent broadcaster and advert-free content, without all the issues around enforcing a per household fee.
I do think it needs more independence from the state too though, if the independent regulator Ofcom were given stronger powers over the BBC, and the funding was dictated by legislation in say 10-year periods, then there's no reason why we couldn't have a state funded service firmly out the grasp of whoever the incumbent political party is, as recently it has somewhat disintegrated into a Tory mouthpiece (Fortunately Ofcom are starting to look into it, but it's too little too late).
Still even I'd rather have one of our many broadcasters be a Tory mouthpiece than a mouthpiece for whoever the biggest payer is like with every other broadcaster. It's quite common for the whole UK population to overwhelmingly unite behind specific policies against the commercial sector, on issues like fracking or privatised healthcare for instance, public opposition to intrusive commercial/private practices are essentially unanimous, and these large corporations are now the greater and more powerful evil that needs to be held to account.
At the end of the day, our interests will always be better served by those we choose to elect and who always face the risk of de-election(Well, we may need Open Selection/Mandatory Re-selection for that to always be the case) than random billionaire dudes who got to their position by exploiting foreign workers and siphoning out public funds.