Reddit admins chose to strengthen censorship and guidelines against anything that could be considered lewd.

I am not sure that this is quite correct; I got the impression that the NSFW content management / content restriction aspect was chosen to be the palatable or defensible thin end of the wedge on the road to creating increasing disparity between what was available via the official app and what could be accessed by third parties via API - my guess is that we would start to see gatekeeping of things like sport content and maybe some sponsored subreddits etc.

Reddit admins chose the path of strict regulation and higher prices, and then made the pricing for API access exorbitant.

Exactly; the impression I got was that they wanted third-party apps to be financially non-viable.

Ultimately, Reddit was trying to force traffic (and revenue) through ONLY their app

Absolutely. And by the time they killed off Apollo, I was already browsing Lemmy.