Step 2, demand compliance.
Step 3, upon not hearing of compliance, levy fines.
Step 4, upon non payment of fines, declare in breach of (2).
Step 5, block site from UK using DNS, in the same manner as torrent sites etc.
5 was always the goal, 2 to 4 are largely just performative.
If you're a British football fan and want to watch every live televised match, you'll need to pay £75 a month for subscriptions to both Sky Sports and TNT Sports. That won't actually allow you to watch all of the matches that are played, because for weird historical reasons there's a TV blackout on matches played on Saturday afternoon - even if you've paid for your subscriptions, you'll only be able to watch about half of all league matches on TV.
Alternatively, you can pay some bloke in the pub £50 for a Fire TV Stick pre-programmed with access to a bunch of pirated IPTV streams and a VPN to circumvent blocking, or get a mate to show you how to do it yourself - no subscription, no blackout. As a bonus, you get free access to Netflix and Disney+ and everything else.
Sellers of dodgy Fire Sticks occasionally get caught and imprisoned, a handful of users occasionally get nasty letters from the Federation Against Copyright Theft, but it's too widespread to really stop. Practically every workplace or secondary school class has someone who knows the ins-and-outs of circumventing DNS- and IP-level blocking; the lad who showed you how to watch live football on your phone or get free Netflix will be more than happy to show you how to access adult sites without verifying your age.
https://www.gov.uk/government/publications/illicit-streaming...
https://en.wikipedia.org/wiki/English_football_on_television...