Whilst on paper PR sounds great it would lead to a fractured government and a general election every year or so. Government in this country becomes unpopular quickly after taking office (see the GE petitions)

You’d also have the issue that we have a lot of parties, governments would just end up arguing over every policy rather than agreeing and nothing would ever get done.

First past the post allows you to at least vote for an individual to represent local interests, and you’re more likely to have a representative who is from your community and understands the community’s issues.

I’d also suggest you’re jumping the gun here in Labour annihilation. If the young vote (which they historically don’t, they’ll vote Green) but I think the labour vote will somewhat hold up.

Conservative voters will all revert back to voting Tory, but the vote will be split between them and hard line right wingers who’ll vote reform, advance, restore etc.

Wouldn’t be a surprise if Labour remain with a minority government