That makes absolutely no sense. For one, it's not like there are people who have a billion dollars salary - that's just not how it works.
Second, if you make a hard cutoff like that you disincentivize producing anything above that cutoff, so nobody would ever bother actually making that money if you take it all away anyway.
Third, if your taxes are too too drastic you'll just drive those people and their investment (which - like it or not - still usually has some positive impact) away creating competition for yourself in regions with less strict taxes effectively kneecapping yourself.