It has nothing to do with the amount of the price, the scheme (charge per request, not /user/month) makes third party apps impossible on purpose. Not to say that this abrupt and unannounced dumping of beloved community apps is just the latest misstep of a long string of anti-user moves from Reddit. They had it coming, but their estimation is that a large majority will keep silent. Let's see - Twitter had also not truly crashed yet on their grand way to profitability...

Even if the API price was reasonable, Reddit only gave 3rd party apps 30 days to prepare. You can’t come up with a decent pricing model, billing infrastructure, and incorporate the logic in your app in that amount of time. It’s just overall very hostile and unreasonable from Reddit leadership. The biggest apps are forced to shut down because if they stay up, the millions of dollars in bills are going to start flooding in.

Propaganda is gaslighting users that the apps make API requests.

No, users do, using their web client of choice for the site.

Reddit is fighting its own users, and fighting what it used to mean to be a web site.