I don’t personally listen to podcasts often, but a Spotify client called Spotube can play the same Spotify podcasts ad-free.
On Android you can get Spotube from its official Git site, or just from the F-Droid app store. iOS/macOS guides are also in the website.
For educative scientific YT channels I’d recommend Veritasium, The Action Lab and NileRed to name a few. They produce top quality scientific videos about really interesting phenomenas and experiments. And the best part is they make the concepts simple to understand without the need of a degree or smth lol