WinRAR did make piles of money by focusing on the commercial market. They really didn't care if home users went past the free trial period, but they did care if you were a business.
The current revived version appears to be tied to a content streaming platform for "creators," and also sells NFT's. The mothership certainly gets a cut of all of those sales. Just like seemingly every other techbro venture nowadays, their business model entirely revolves around being a "service," and the media player itself is apparently just a side hobby. (Note that this is basically exactly the same mutation that happened to Napster. That worked well.)
Otherwise, the answer is sponsorship by a corporate sugar daddy. Even the OG Winamp was sponsored by and then ultimately bought outright by AOL.