I’ve not got kids yet so not really helpful to your question. But I’ve seen enough of parents who just give their kids tablets and smartphones (Unfortunately in a couple examples I know, it's because they can’t be bothered to parent). Not only do the kids end up getting hooked on the devices, but the content they’re consuming is… worrying.
It’s enough that my partner and I have already spoken about how we will try to raise ours. I don’t think complete isolation from tech is the answer, it can be a great learning tool after all.
But I’m going to make sure I use it with them in the earlier stages of life. They won't just have their own devices, and they won't be able to use it all the time. We're going to promote reading and other activities, being outside, crafts etc - If they show an interest in STEM/STEAM stuff that's cool, and tech can be used here - but it doesn't have to be connected to the internet all the time. I can build little hobby electronics with them, we can set up Raspberry Pi's, we can create stuff in software and even play games like Minecraft. But together, and in moderation.
Obviously we won't be forcing them to only use tech with us, or watching over them super strict later on - but for the earlier parts of life? You can be sure their introduction to technology will be more than "Here's a tablet, go play games and stop being a bother"
You're right - I was one of those people (Not running back though) I sometimes fell into the trap of just going to Reddit /r/popular and scrolling. After many attempts of telling myself "No, I will just have a nice curated feed on home instead, with only hobbies and interests, and I'll only look at the end of the day"
Next thing I know I've gone and clicked /r/Popular again and I'm scrolling down. And it was bad because while, sure, I sometimes saw some cool or wholesome stuff, I also saw a lot of bad. People being cruel, drama nonsense, even more extreme stuff like death and gore. It all bubbles up there in some way. It was not healthy for me to keep visiting it.
Once I ditched those platforms - things started looking up, and I've even gotten way more productive too.