I found that for social media, platforms like Mastodon feel more comfy and less commercialized, whereas for chatting with other people either 1:1 or group chats across various apps feel nicer without being directly tied to a social media platform. At the same time, platforms that are more focused on a particular set of topics/activities like Reddit/Discord/HN/... instead of people just trying to advertise their lives or build a brand in a sense (the likes of LinkedIn as well) or whatever are more meaningful to me.
To some degree, it probably has something to do with the size of those communities: Mastodon is niche enough not to get spammed with as many bots or adverts or people trying to push a certain narrative, it going under that radar is one of the best things about it, instead it's more organic content.