Today I saw an article about the 20th anniversary of OpenStreetMap. Which as open data is using both free and paid servers. Also take in mind computing power and storage is a lot cheaper nowadays, and will keep getting cheaper by moore's law. Of course we do heavier type of applications too, but at least for notes I think free relays can work as free servers work for 20 years with map tiles. https://techcrunch.com/2024/08/10/one-man-decided-to-take-on-google-maps-20-years-later-openstreetmap-is-still-going-strong/