I don't think it has anything to do with Germans or French people. Hetzner, Contabo and OVH are just popular (and cheap) providers to host bare metal instances, and they're not big tech. Those two reasons are probably why we're seeing a lot of them.
The major cloud providers charge too much for bandwidth to make hosting a social media site there viable.
AWS/cloud providers are like buying bottled water, instead of getting better stuff for effectively free. That's how cheap bandwidth is in reality. Free. AWS markup on bandwidth is insane. Immense. EG, 1 trillion times the cost, or some such.
(With AWS's size and scope, its peering capability, yes... 1 trillion times markup is likely conservative, for what they charge for bandwidth)
Most baremetal stuff is sold on the size of pipe, not on data transfer.
At the risk of invoking Godwin's law, I think it genuinely does come down to the Nazis and Gestapo and what those groups did with the information they had. Not saying that every German thinking about their privacy is thinking about that, but it does kind of de-fang the "nothing to hide" argument and that allows a bigger pro-privacy culture to develop.
At the same time there's some notable exceptions, such as their rules around impressums.