>Overall, text just works better for the kinds of content I'm interested in.
You're making such a weird argument. Podcasts are not replacements for books. Books do things that podcasts can't. Podcasts do things that books can't. Don't want to listen to podcasts or music? Don't. Read your books and be happy.
>Podcasts are also completely inaccessible to search engines.
That's a problem for search engines to solve. In principle, search engines could auto-transcribe podcasts and index that.
>If I want to find the podcast where they talked about an interesting thing that I want to revisit, and it's not in the episode description, it's basically lost forever.
Again, indexing is not something that the medium needs to solve. That's for others to figure out. Text is easy to index. Images are harder to index, audio is harder still, and video is probably the worst.
As a personal anecdote, I DO need to be fully engaged to consume audio in the same way as text or video. Your example of vacuuming is a perfect example, while trying to pay attention to the carpet I'd stop paying attention to the podcast, and i'd have to rewind, which I find tedious.