There aren't these kinds of incentives (nor clear rules as to what content is considered on or off topic) on any mainstream social networks, and the operators themselves would rather have an disorganised army of idiots wasting time spamming random crap (and clicking on ads) rather than having a community centred around a set of guidelines and a common goal. Like if I sign up on Facebook, Twitter or Instagram today there isn't a FAQ post to let me know what's the objective of the platform, what content should I post, etc. Worse, I can isolate myself in echo-chambers by following the wrong accounts (which the platform will encourage by recommending more accounts like those) and this is how you end up with misinformation, etc.

See also Twitter; it used to be for mostly tech people due to the relative complexity and unwritten rules of the platform acting as a gatekeeper preventing idiots from coming in. If you put in the time to learn and understand what the platform is about and go through those barriers then there's a good chance you'd be a productive member of the network, so overall it self-regulated quite well. Unfortunately, these users are also the least likely to click on cancer aka ads, and since big tech is allergic to letting people actually pay for a service they'd rather dumb down the platform and open the floodgates and the cesspool that is today's Twitter is the (predictable) result.