Already did. Purged all my Reddit bookmarks and account.
Generally: You have to be the change you want to see in the world. If you want to change others, change yourself first.
I don't think the mindset "I need to reach that big number of people over there so I'll just be over there as well to teach them" works, or leads to the goal you want. Even though it seems reasonable at first glance. This mindset just leads to you giving the other people AND yourself more reason to never leave from there. Which is contrary to what you want. If you want others to switch to better alternatives, move yourself first, help grow the alternatives, and they will sooner or later also become interested in joining. Things like the latest Reddit and Twitter fiascos also show that no huge proprietary social media platform rules forever. The time to change to better alternatives has never been better than now.
It took me way too long in life to realize you can't change other people. There is a famous Persian poet (Rumi) who stated "when I was younger I wanted to change the world. Now I want to change myself." Really it's made me a lot happier as well. No more stressing over why people don't believe me or spending hours in pointless arguments. Just focus on what I know is needs improvement in my life.
I should have left reddit a long time ago and I even tried a few times, but the lack of an alternative to keep me connected (it was my only social media) always had me coming back. So I'm proud to say I'm at least a week without any reddit whatsoever, not even peaking in my rearview mirror at this point.
People can be changed, it just takes time and it might be hard. It also depends on how open-minded they are. Also, with technology, you have the additional problem that many people still don't understand most technology even on a basic level, and they might not know anything better than what they're currently using. If you show it to them, it might not even be so hard to get them to change. So I think there are a lot of factors at play. But even in the hardest cases, hard doesn't mean impossible.