It seems odd that there's a stringent ad approval process when the site proudly lets Redditors post any garbage they want. I'd have expected anything SFW and not obviously fraudulent to be allowed.
It's obviously not very stringent. A lot of the ads they run lately are outright scams, including even advertising Scientology: https://i.redd.it/6cd1ricqc8j11.jpg
It sounds bureaucratic, not stringent. Lots of forms to fill out, and a lot of order, and probably not even many requirements to meet (but a lot of different ways saying you did meet them) but lost its purpose a long ways back.