Based off tax return and make tax fraud hurt. Sure some people will still optimize for tax avoidance but will be far fewer than the totality of those wealthy enough to disregard rules at present.
Every European country (even Finland) has harmonized rules about "tax residency". The rules are simple: If you actually and honestly live there at least half a year and one day of a calendar year, that place becomes your tax residency for that year.
The rich person buys a property in Monaco and goes there for half a year + 1 day. That year Monaco is their tax residency. They take out dividends from their off-shore (or Netherlands) holding companies. Boom, perfectly legal personal income taxed at super-low (or 0) rate that Finland has no idea about.
Then the person returns back to Finland and again accumulates their income into the holding company for a few years until they run out of whatever they got as a dividend.
Repeat until...
But that's how it goes and there are other countries you can use to evade taxes too.
Not sure what's the distinction between rich and wealthy, sounds the same to me.
Rich people have high incomes, wealthy people own a lot of valuable things (properties, land, art, stuff that keeps its value).
New money vs old money/generational wealth pretty much.
I have a good enough tax regime where I live in Central Europe - for 2022 I paid 8% including income tax, health and social insurance. But I'd definitely consider doing this if it was over 20%.
But if Switzerland can do day fines, I think other countries can as well, it's the will that's missing and nothing else.