Not quite immediately post-45. That was when the modern welfare state was being put together. Winning a war was the peak of state capacity. Things were still going OK around 63 and the "white heat of technology" speech (why can I not easily find a full transcript of this?). Wheels came off in the inflation era leading to the "winter of discontent", followed by a massive and explicit backlash against socialism and in favor of individual profit. Thatcherism. North Sea oil solved the money problems, but papered over the more structural problems. Blairism managed a second financial services boom, but then .. 2008. And we've never recovered.

Here's Wilson's White Heat speech: https://web.archive.org/web/20131006142325/http://nottspolit...

I agree it's concerning that major speeches like this are so hard to find.