I've never seen an Atom formatted podcast. NYTimes and WSJ each have a whole page devoted to their RSS feeds, I've never seen an Atom feed from either of them. It caught on sorta but didn't get the traction of what it was designed to replace. (Not saying this makes it Bad, btw.)
That's a good point. Podcasts are still (almost?) exclusively RSS 2.0. IDK if this is just momentum or Apple rules but I don't think I've ever seen an Atom podcast.
But many podcast clients actually still support Atom (probably using a feed library that supports various formats?) and basically all non-podcast feed readers support Atom.
I think it caught on well enough, platforms such as Wordpress still support it out of the box (I just checked my blog, it works).
I liked Atom's clean design but it felt it was mostly pushed by Google (I may be misremembering) and in the end the syndicated web faded into obscurity anyway.
RSS 2.0 is kinda an unspecified mess, and at least 15 year ago, if you wanted to be compatible with the majority of content you needed some weird heuristics to detect which interpretation of the spec a given feed was using (lol).
And Dave Winer was strongly against ever clarifying the spec, and that’s part of what led to Atom.