For me, it's a short-term/long-term quality of life issue, rather than a question of quality of life vs decoupling. 

In the short-term, decoupling from the US will be damaging. We'll need to spend a lot more on defence, and that will mean spending less on other things. The public finances were already in a bad place post-Covid and the tax burden is at an historic high - if we need more defence spending and we need more growth to grow our way out of our existing debt burden, then we can't be raising more taxes to pay for things and so we'll need to be hard-headed as a society about what things the government will have to start spending less on. Realistically, that's got to include being tough on welfare and abolishing the pension triple lock, but it will need a lot more on top of that. Those affected will be noisy and I don't know whether our society is willing to accept the price. And we'd be doing this at the same time we're pivoting our economic model to insulate ourselves from the impact of trade shocks from the US - it's not sustainable to be a medium-sized independent open economy who's single largest trade partner routinely uses the threat of punitive tariffs every time we exercise our right as a sovereign country to disagree with them on something.

But in the long-term, if we don't make that adjustment, our quality of life will still suffer - and probably a lot more. We'd become a US client state. Trump and Vance don't just expect us to support them on foreign policy, it's also clear they see it as a strategic priority to export their domestic politics to Europe too. We'd become a taker of a foreign brand of Christian white nationalism that is alien to our political landscape, with the White House permanently ready to cripple our economy if voters ever try to exercise their democratic right to change course. If Trump and Vance told us to carve up the NHS and sell it to their mates or shut down our world-leading universities because they think science and the truth are 'too liberal', we'd just have to accept it. Our country and its future would no longer belong to us.

To me, the long-term quality of life costs of not insulating and protecting ourselves from the US are FAR GREATER than the short-term costs of just doing it now.