I suspect that not all social media is equal. And that even within the same site, people can have radically different experiences because social media is always tailored to you in some way. On sites like Reddit and Lemmy, it’s tailored by the communities you subscribe to. On Mastodon, Facebook, Instagram, or Twitter, it’s tailored by who you subscribe to and sorting algorithm.
I suspect that the difference in who/what you subscribe to would actually be bigger than the difference by site. You can find really toxic, harmful content on every site and you can also find really positive, helpful content on every site. Though some sites make it easier to be exposed to harmful content.
Eg, the Reddit/Lemmy model benefits from the fact that moderators can apply strict rules to communities you subscribe to (such that you only have to curate broad communities). By comparison, many other sites would let pretty much anyone reply to posts by specific people or groups and while the original poster can usually block or remove replies, that’s not scalable and posters often won’t.
But that said, we can’t forget that Lemmy is still social media. It still has many of the risks that social media has and we must be cautious of that. I firmly think we can ensure Lemmy is better than all other forms of social media (I do think the Reddit/Lemmy moderation model is strictly superior), but there’s a lot more we can and should do to ensure Lemmy is of high quality and that people can and do curate their feeds responsibly.