OpenStreetMap tile servers aren't really meant to be used for this. They do allow some use, but are also subject to throttling if your application puts too much load on their servers.

> However, OpenStreetMap’s own servers are run entirely on donated resources. They have strictly limited capacity. Heavy use of OSM tiles adversely affects people’s ability to edit the map, and is an abuse of the individual donations and sponsorship which provide hardware and bandwidth. As a result, we require that users of the tiles abide by this tile usage policy.

https://operations.osmfoundation.org/policies/tiles/

Just so you know, I make it a point to report to OSM maintainers any relatively sizeable app using their tile servers, just so they can be banned.

The default OSM tile server is not here to serve your startup.

That is usually out of the question, because raster tiles don't allow you to customize the map (colors, which features to display at which zoom levels, etc). I find openstreetmap way too busy as a backdrop for data.

As I've said, the solutions are there, and there is an actual demand for cheap vector tile hosting without all of the other cruft that is bundled in the commercial solutions but isn't actually needed.