GNOME Maps and the tile problem

Pretty much nobody (appart from OSM editors) use the raw OSM data to render. They all do some initial filtering, keeping only the data they know to interpret, and sometimes simplifying the geometry. Some extract a region and convert it to a binary format more suited to rendering/routing. Some put the extracted data in PostGIS and render pngs tiles from there. Some do the same step but render vector tiles instead.

Vector tiles has been the focus of a lot of OSM development in recent years, because they are much more flexible (think changing the display language, optionaly show buildings, etc) while puting a lower load on the server. But it's difficult, and hasn't overtaken png tiles in popularity yet.