> And your solution is... what?
Well, like you, I ran a personal mailserver for nearly 20 years. Initially I had trouble delivering to gmail and Hotmail; those problems resolved themselves after a few years. My ISP now hosts my mail, using the same infrastructure that I used to use: Postfix, SpamAssassin, Dovecot, Sieve. I use my own domain.
Obviously email isn't the same as social media. I never liked the social media landscape; I've always seen the internet as fundamentally distributed, and I always regarded MySpace/Facebook et al as a trap. I have an old Google account, but I never use it. Otherwise the only social media account I've ever had is HN.
I'm not in business, I'm not selling anything. Also I'm rather reclusive; I don't need a large circle of friends, about three has mostly been enough for me. So I'm not like everybody else, and I can see that for some people, there isn't much alternative to the giants.
I'm against designating them "critical infrastructure". That would simply deepen the moat. If they really are critical infrastructure, then they should be provided by the government. What they do that's useful isn't hard; what's hard is the part that isn't useful - advertising, and constant user-engagement.
I think something like Mastodon probably has the potential to defeat the giants. It's truly distributed, and not under central control. Mastodon seems to be designed as an alt-Twitter, based on short messages. That doesn't suit me, but I expect something like a long-form Mastodon will rock up sooner or later.
Regarding victim-blaming: this is like making a deal with gangsters. I have every sympathy with the victims; but if you place your business in the care of a giant, with no proper support channel, that don't take money off you for the service, then your only recourse is to ask for your money back (i.e. zero). You can't even sue for breach of contract. That's an extremely squishy foundation to build a business on.
Facebook has lasted rather well; Twitter seems to be going down the tubes. MySpace died a long time ago. But Facebook will fade away - they all fade away. What lasts isn't websites and services; it's protocols.