Harmful content => Any government regulation of harmful content will probably hurt small players more, since it's a big fixed cost of moderation. But everyone will realistically pay that cost anyway unless they're something decentralized like Mastodon.
Elections => Nothing to do with size of platform I think, they're just saying that it's disingenuous since filter bubbles are more important. I disagree, election financing is super important and as another poster said filter bubbles are as old as print.
Privacy => It says that GDPR is terrible for small companies, but without any evidence (or spec of "small") I think for anyone the size enough to be looking to challenge Facebook it's not a big deal, and broadly I like GDPR. "Don't store people's data unless you need to, and ask permission". Not a bad first effort to trying to fix surveillance capitalism.
Making data portable => This definitely, definitely would hurt Facebook more than help it. Noone is sitting on Instagram thinking "I'd swap to Facebook if only it was easier". They're the monopolist with the inferior product + network effects, that narrative makes no sense at all.