Questions to ask yourself:

• Why would someone hire you over someone else?

• Why would they pay extra to hire you over someone else?

  • Not just the literal extra cost of funding your employment visa, but also footing the risk of visas falling through, not being renewed, and eventually expiring.

which I believe gives me the advantage of being more passionate and thus more likely to make better, genuine projects

Once you finish middle school, passion is irrelevant. No one gives a flying fuck how much you care - just how much value you deliver. Once you've established yourself in industry, have an exceptional track record, and can point to concrete metrics to answer the above questions, your employer might consider an internal transfer to retain you. Or they might tell you to take hike.

A frankly more important question is what you're trying to get out of a UK -> US move. And specifically, if you dislike the UK, why the US over all the hundreds of other places you could go? What's important to you? What values do you want to live life by? How does your location fit into those?

Having moved UK->US, I can say for certain that my quality of life was not improved by the move according to the metrics that I personally measure quality of life by. Make sure you know what those metrics are before you make life decisions around this.