PoV: I'm a dev and I want to put my code out there. GH is basically a social network that aims to show my project to like-minded folk, no other service does that. Personally I enjoy this social aspect and occasionally check on GH feed to see what the circle around me is doing, to catch sw trends.
Why would I be concerned about privacy when the idea is to make it public? GH is just a free host that happens to be most popular and it would reach most eyes, the best chance of getting back some contributions.
If I used any other git hosting service - my code would be scrapped just the same, but would reach almost no human. If I tried to publicise the project myself, the other devs and potential new users will be far more likely to click on a GH link than any alternative. Self hosted solution would get least clicks. People like familiar URLs that lead them to "safe" sites.
Among big tech, I actually prefer Microsoft over Google, Meta and others. Yes, MS is just as disgusting, but at least they are grossly incompetent and only manage to execute a fraction of evil schemes they come up with. It's funny to watch actually.
It's not even about skill atrophy, it's more subtle. You can quickly relearn forgotten skills.
Unlearning a habit, on the other hand, is much harder. If you get into habit of reaching for AI anytime something hard needs to get done it's going to wreck your internal motivation and reward system. meme_historian describes it really well in this thread, I noticed the same thing happening to me.