You are correct that your data isn't particularly impactful for these platforms - but you're also overestimating the value that many of these services have. A fair few of them have competitors with better features and privacy offerings so the only reason you need them is purely for the network effect of everyone else using them.
If there is a substitute and I am not time constrained 100% i'm switching. But I've been in a situation already where a platform I'm using required me to face-up. I can't even remember which to be honest but I had no alternative or recourse to refuse. In addition, in the UK company directors are legaly required to face-up to Companies House and confirm their identity, so they have my face too. Ah, and so is every single CCTV camera around London. I don't know how to fight this particular battle.
The competitors will be also regulated. It’s a slippery slope.
Just because the network effect is why you need them doesn’t make that need go away.
And increasingly, everyone isn’t using them, even if they’re on them.
I’m on Insta and WhatsApp and I use them a few times per year. I’m on Messenger and have seen a dramatic dropoff in messages. I’m on FB frequently and notice only a small fraction of my friends bother anymore and it’s become an interest platform to make up the lack, so I’m trending toward less time there. I’m on Twitter/X but check in maybe once a month.
I may not be a typical user, but I’m probably not unique either.