Rather than imposing posting limits, I think the problem is more to do with the upvote bots, whales and general low quality content which gets high rewards.
I find it stupid that a photo of a cat, no text or anything, just a photo can amass over $100 or $1000, whilst a well written article which someone spent hours on, writing, researching and editing, may get under $1.
The issue is that the ones with the most power have the most control. I don't personally believe that imposing based on number of posts per day addresses the problem at large.
If say we could find a way to discourage people using upvote bots, and / or posting junk, then that is a far better solution. Which honestly, the not upvoting junk by people will lessen the amount of junk, as if it not being upvoted, then there is less incentive to post junk.
Let me know what you guys think, happy to be convinced otherwise :)