I don't know about EU immigration, but a university degree greatly helps with US immigration; even more so if the degree was attained in the US. It's certainly possible to do well in this industry without formal education, but it would be a lot harder to immigrate. Jumping through the hoops of formal education shows the ability to jump through society's hoops, which makes you a better candidate for immigration and integration into society and the hoop jumping that's required.

> Anyway, an inevitable question arises: why haven't I enrolled earlier?

You answered that; you weren't prepared, you took the time to prepare. Easy peasy. Actually, a lot of universities are looking for the diversity that older students bring, even when older student is just 10ish years; you've probably got a lot of life experience that others don't have.