I would say the most common types of money-based communities are likely pay to access (exclusive content, courses, etc) or pay to support (via donation)… this is much easier because they payments are larger and consistent. There’s still moderation value here, because people don’t want to lose access to something they paid for.
The problem with the smaller transactions (post, upvote, etc) is that at small scales the friction of actually making the payment and the payment processor fees create a barrier that make it not worth it (this is maybe less of an issue in some countries with better peer-to-peer payment systems).
There have been attempts to solve small transaction friction, like Flattr - Wikipedia… but the complexity of understanding and using a system like this still creates a barrier that makes it hard to break into some kind of mainstream popularity. Cryptocurrencies also have this problem.
One modern way to avoid this is to bundle up payment in a package that gives you in-app currency “gems” or whatever you want to call them… many video games are doing this now. Discord also does this with their “Nitro” subscription to some extent (you pay $10 a month and can give “boosts” to 2 servers for extra features everyone can use).
This comes with its own problems of having to spend more than what you initially need, which I’m sure some companies love to take advantage of… things like selling some $1 in-game item, but making the minimum purchase $5.
For a completely different take on this, in addition to a sign-up fee, the long-running somethingawful forums offer an adversarial transaction: for $5 you can change your own title on the site, for $10 you can change someone else’s.