Nearly agree with everything you said.
But maybe Reddit is okay with a few 3rd party apps surviving if it means they can charge such a ridiculous premium on API requests. Perhaps they didn't think any dev would be crazy enough to take them up on their offer. But at that point, they're raking in so much money that they might not care those users are on a 3rd party app.
I think they said there weren't any ex-Twitter employees working on Threads.