Under current economic conditions, economic wealth is necessary for the functioning of the economy

is it required? to an extent, yes. but do we need 60% of everything to be owned by 10% of the population?

As for the Capital flight, that is a myth, even the implementation of straight wealth taxes don't see great multimillionaire migrations, because taxation isn't a very strong factor, in fact a golf course or tow is a stronger pull, example Scotland vs Ireland when the UK was still part of the EU saw more ultra wealthy live in Scotland, a region with a higher tax rate, than Ireland, primarily for golf courses.