Podcasts are a leftover from the non centralized and non-monetized internet of the past. Because is that most Podcasts are still available as rss feeds, so you should only ever get adds if they are spoken by the Podcasts hosts. Ate you taking about those? Only something like sponsorblock would help against those. I use antennapod (fdroid) on android to listen to Podcasts. Sine hosts always start their podcast with an add, but you can autoskip the first minute of a certain podcast with antennapod every time. It has a setting for that. Antenna pod itself is foss software without adds.