Well, if I could afford a house worth a million pounds in the UK on a 30k pound salary, I should move over there!
I completely agree with you about the healthcare system and vacation time.
I think the reason the US doesn't have a universal healthcare system like the UK is simple. Here is something that I have noticed about social safety net programs:
1. It is EXTREMELY difficult to establish social safety net programs (it takes a lot of political power and will, and there is resistance from the wealthy and powerful, who launch media campaigns to scare people away from such programs and stigmatize them).
2. Once a social safety net program is established, people realize how much they like it, and it is EXTREMELY difficult for politicians to take it away. Even right-wing politicians will largely concede that they need to protect these programs.
Because of point 1, social safety net programs typically can only be established during extraordinary times when people are desperate or receptive to big changes for various reasons. The NHS was established in the post-war period, for example. The US made various strides in adding to the social safety net during the 1930s, 1964-66, and 2009-2010. But the politicians in power fell short of establishing an NHS-style system during these very brief windows of opportunity. Outside of these once-in-a-generation opportunities, it is virtually impossible to get anything done.
Long story short: the UK left made better use of its once-in-a-generation opportunities than the American left.
Other than that, I see similar political problems in both countries. People keep voting for right-wing politicians who will screw them over economically instead of voting for people who are proposing new programs that could help them. Why? Right-wing politicians know how to scare people away from changes that could help them, and they know how to distract people by getting them to focus on culture war issues.
Americans keep having to choose between corporatist politicians. One corporatist party (Republicans) caters to racist whites who hate black people and immigrants. Another corporatist party (Democrats) pretends to be progressive, but focuses mostly on identity issues instead of economic issues (because their corporate masters don't mind them focusing on identity politics, but they do mind economic reforms that would make them pay more). In the UK, people generally have to make similar choice, but you had opportunities in 2017 and 2019 to vote for a Labour party that was actually proposing real, sweeping changes that would benefit the average person. Americans have not had that opportunity in my lifetime.
You're doing the right thing by wanting to sort your head out before making another committment.
Too often apne view wives and husbands as if they're livestock; one's gone, time for the other one immediately. Didn't work out for whatever reason? Nevermind, third time's a charm. Cheap, dehumanising mentality.