Ya. That is a large part (not the only reason) of why Huffman gambled and lost on killing 3rd party apps. People using Apollo, or any other app that wasn't the trash official app, weren't getting ads at all or were giving their ad dollars to a third party. By killing third party apps, that forces anyone who actually wants to use Reddit to use the official suck ass app or the garbage desktop site which also had alt options that used the API. When users are funneled into only using official Reddit products, that means they're only consuming ads that Reddit makes a profit from.
I used Bacon Reader for almost ten years. It didn't have ads for half a decade and when ads did come, it was a non intrusive banner ad at the bottom. The Reddit app is riddled with obstructive ads. So is the website unless using an ad blocker. Reddit when used the way the admins want, is just one ass blast of shitty ads.