However instead of regulating everyone, banning one player and leaving the opportunity for others (including new players) to continue "bad thing" is not a good solution, is it?

Meta is already extremely regulated, both by governments and externally managed processes like the oversight board. If TikTok were an American corporation that played by the same rules, it would be a massive improvement.

It's better than doing nothing!

If you want to argue for more laws, go ahead. But don't do this whataboutism where you pretend like you care about these issues, and argue against ways of stopping, at least some of the bad things happening.