The solution to that is to aggressively enforce antitrust laws already in the books, not to oppose "laws of responsibility" because it might have disproportionate impact on small companies.
Note that Germany's "Facebook law" doesn't apply to social media platforms with less than 2 million users, which shows they took steps to protect small businesses from the compliance burden.
big tech has basically monopolized the market, but if we enact laws of responsibility, they could be ones that make it even harder to disrupt the monopolies already in power