Meanwhile it would be news to me if any of my friends in Mexico and Spain (the two places I spend time in nowadays) listen to podcasts at all. I also listen to Mexican/Spanish podcasts to practice the language, and there just is no contest with the top 1% of US podcast -- what most people are listening to. So you need to also have a sufficient proficiency in English to get into podcasts.
The sibling comment focusing on public RSS feed is looking down the wrong rabbit hole when there's a simpler answer: US has high absolute and per capita numbers for podcast listeners which is what you need to have a culture of podcast production.
In HK and Japan, while it is still quite widely used by the relatively more tech inclined people, you can't randomly ask a new friend if they like any podcast and expect them to know what you are talking about.
Also, English is a widely used language. My native language is Cantonese, but the amount of shows in that is very low, and I'm more comfortable with English than other Chinese dialects including Mandarin, so I listen to mostly English podcasts. I imagine similar thing might happen in countries with more than one spoken languages. I know some Indian friend who has a podcast that they did in English even though the topic and target audience are mostly Indians as well.
There are exclusive "podcasts" on Spotify that are not publicly accessible and not distributed via rss.
There are other forms of spoken audio contents that are publicly accessible but not distributed via rss.
Open RSS-based podcast ecosystem is less developed outside US, for countries with comparable (or larger) population.
There are many walled garden audio platforms in countries like China. For example, probably most of you haven't heard of Lizhi FM [0], a "podcasting" platform from China that just went public early this year. Most of its audio contents are not distributed via RSS.
[0] https://www.sec.gov/Archives/edgar/data/1783407/000119312519...
An audio program that isn’t published via an RSS feed is no more a podcast than the proprietary pages that AOL use to host are “web pages.”