On mobile it takes up the entire screen

For decades the UK was run by the sort of people who were totally A-OK with lots of stuff being ruled from Brussels, and who even wanted to accelerate that trend. Brexit took away the rule from Brussels and the constitutional crisis that saw 50+ MPs get kicked out of Parliament got rid of the most extreme elements of the Tory party at least, but neither suddenly replaced all the politicians and civil servants who never really wanted Brexit to happen and have no actual ideas for what to do with the new powers.

Getting rid of the stupid cookie banners may seem obvious, but there's a lot of obvious improvements that can be made like that. Sunak would rather host AI summits than actually make them, however.

Because the UK has the choice to keep good EU laws and dump the ones they don't want.

GDPR and cookies are good for the user. they give the user the choice to tell google etc to go away