I don’t know when this started but I noticed it for the first time a few months ago. Some podcasts will have preroll ads that are obviously tailored to me since they are not in the same language as the podcast, instead they are in my native language and if I connect to a VPN in another country the ad will change to one from that country. They also seem to appear regardless of podcast app. I have used both AntennaPod and Spotify. AntennaPod is free so I guess they source their podcasts from some third party website that could be adding in the ads. But since I am paying for Spotify I am expecting not to have to listen to any ads. So who is adding in these ads? Can I get rid of them or am I just stuck with them?
My guess as to the “why” is that it’s just another example of enshittification. Podcasts were essentially a bubble that everyone was trying to get in on, but the amount of low quality (not just production but also content) flooding the market devalued it significantly and listeners and subscriptions began declining. Everyone is trying to squeeze as much money as possible out of it now, which means there are even more ads on top of all the ads and cross-promotion that come baked into an episode.