That's how you make people lose interest in the country — exactly what OP is complaining about. If you want to stop brain and capital drain, taxation should be the last thing on your mind.
There's a tipping point though, right? I think the right question is, how do we find the correct threshold?
Otherwise, there will be an asymmetry in which the "brains and capital" will get all the benefits of taxes with little to no skin in the game. That implies society serves the economy and not the other way around.
> Whether the government wants to tax it is a different question. Usually they do not.
We're talking about a formerly socialist European country here. Not everywhere is USA :)
Income tax in Slovenia goes up to 50% and VAT (similar to sales tax) is an eyebleeding 22%. Capital gains taxes can be as high as 25%. Slovenia is not afraid to tax people don't worry.