Nonsense. In many cases, vendor lock-in and the network effect present a substantial hurtle to living free of these companies. Sure you can quit Facebook, but they'll still build an internal profile about you. You can also tell your mobile carrier to go f* themselves and get a ham radio - but unless all of your friends and colleagues do the same thing you'll just be talking to Major Tom up in his tin can.

Freeing yourself from the grasp of these companies is hard enough for the tech savvy. For laymen it is virtually impossible.

If you quit using Facebook, what does it matter if they have some bits about you?

They’re my goddamn bits, that’s what’s the matter.

They’re bits about you, but what makes you think you own them?

I suppose the general fear is that we are the product and we don’t know what we are being sold for or to whom. If they are so sophisticated they can infer behavioral patterns after you quit by using your still existing network of friends who didn’t quit then it’s a pretty useful bit of profiling technology with buyers. The only part that ever really mattered is how they monetize the product, us. It’s an unspoken agreement for using a service which has no transparent monetary cost.

So it’s fear of the unknown? I’m genuinely curious why people are so bothered by this. I don’t use Facebook, and use privacy extensions to prevent my agents from using Facebook. It’s like they’re a non existent entity in my world.

I simply can’t prioritize caring about something that doesn’t appear to impact my life in any way. But I’m admittedly not much of a principalled-living person. Too much internal hypocrisy for me to pretend to be principled.

That's it none of their fucking business and that it's quite likely a violation of the GDPR.

Nevertheless there's absolutely nothing I can do about it.

Your question reminds me of the "If you have nothing to hide " fallacy

I don't use Facebook, I'm not on Instagram and scoff on Whatsapp.

They nevertheless maintain a shadow profile of mine.

Would you care to elaborate how I can "trivially switch off" that they abuse my data?

There's not even a need for me to switch to another provider.