The England I first lived in in the 70s is a very different country to the one today.
I was in London just over a year ago, walking in Camden High street past the market when I got chatting to a guy. Over the next week or so, every time I walked past, we chatted again. We became friends, and when I flew back to South Africa (earlier, and unexpectedly, and never got to fly to Portugal or the States), we connected on FB.
Imagine my horror when he deemed the vaccination a conspiracy theory and worse.
That is the England that never used to exist.
I lived in London several times. The last time I returned in 2014, it wsa a very different place to the late 90s and early noughties. The people had become harder, ruder, less generous, etc.
Places change. People change. And the Tories in power (and Blair) did a lot of damage. Then, again, so did Thatcher.
Other than that, I would agree with your sumation. Cornwall is unlikely to split, but that splinter is there. Wales seems to be meandering along.
And Scotland and Northern Ireland, probably, but not definitely.