Strava is the only social network I’m on anymore, and I pair it with a number of weekly, in person group rides. It’s a great way to maintain connections, and a wonderful source of encouragement.
Typical social network dopamine hits probably aren’t great for your health, but when it’s paired with 100 miles of exercise, I think it has a net positive. I’ll definitely admit to pushing myself further than I typically would for those Strava kudos.
That said, I don’t think something like Strava is particularly useful without the in person aspect to go along with it. Heck I don’t even know how you’d gain followers without doing group rides.
I find Strava is also helpful for solo activities that aren't in-person. Knowing that an IRL friend/follower will see my activity pushes me to work harder.