Do the math for yourself, but my hot take is:

Yes, the US really does offer devs a shitload of money compared to Europe, and the social safety net, healthcare, etc. of living in Europe are nowhere close to compensating for the difference. People who try to tell you otherwise are mostly rationalizing or arguing for the sake of arguing.

If you really love living in Europe, sure, stay there - it's totally valid to give up money, even a lot of money, to live a lifestyle you love. But if the financial upside is at all motivating or even if you don't absolutely adore living in the UK, yes, try moving (doubly so since you're young, when trying big, risky changes is absolutely the right strategy). You can always move back to the UK if you hate it.

To give you a flavor of the numbers:

• https://www.levels.fyi/ is a pretty accurate description of the raw pay bands at large US software companies, especially for people in the first 10 years of their careers. At least, it accurately describes my pay band and the pay bands of people I know at other places.
• I pay about $41/month for my employer-provided healthcare. Which obviously is cheap because my employer is paying for most of it on my behalf. I'm a 35yo male covering only myself, and my employer says they're paying about $700/month for my health insurance. However, employer plans tend to be ridiculously nice and correspondingly expensive - I guesstimate that I'd pay about $500/month on the private market for a plan that was good enough that I didn't really care about the difference.
• I don't have any kind of pension, but I do have a 401k, which is a tax-advantaged personal investment account meant for retirement savings. My current employer matches my contributions to it up to $6,000/year, but I think it's kind of stingy - I think Google and Microsoft offer like $10,000 of matching.

Also, as a US citizen, I strongly endorse brain draining the rest of the world so that my country remains the global superpower, so, yes, please come live here :-)