ultimately, it's just a file sitting on a web server somewhere and you need someone to host that file for you. is it you? is it a company? what do they charge? what services do they offer along with hosting? think of it as a very specific type of website and you're buying webhosting for that very specific website.
Discussion
I think the confusion is theres really two pieces of info being hosted. Your media files (audio and artwork) and your rss xml file (aka your rss feed/metadata)
So which ones do both? Only Wavlake?
Podhome is a hosting solution. Publishing is baked into the process by default.
Fountain (with their RSSBlue partnership) is an AiO solution and includes a player as well (just like wavlake)
There are others but I recommend looking at podhome first. There's lots of podcast hosting solutions and just a handful of ones catered specifically for music. Because RSS is open, there are certain standards but you can pick and choose what fields you actually utilize or even create your own as long as theres a compatible app that knows to reference it.