Earlier quoted context omitted.
To hurt enough to be worth changing the fines don't have to be a fraction of their global revenue, they have to be significantly more than the benefit gained from the illegal behavior. According to that article TikTok made $10B of that $20B in the US alone, which puts a cap on their European revenue of $10B (likely significantly less because this ignores Brazil and Indonesia, which according to the linked article are…
The thing is, TikTok is not accused of directly profiting off of this, they are accused of operating as part of the Chinese espionage apparatus. Assuming that this is the case, TikTok is going to be happy to continue paying fines as long as they break even worldwide. And the US is making no serious attempts to rein in this sort of behavior so they've got all that US profit to use.
You mean besides forced divestment under threat of an outright ban?