OSM probably has the best data on golf courses because for many courses, people have mapped each 'golf=hole' as a way, and mapped other golf course features such as 'golf=bunker', 'golf=green', etc.

OSM knows of almost 40k golf courses around the world.[2] This compares to 38k golf courses known to the R&A Golf Around the World Fourth Edition (2021) report and 37.6k courses listed in the NGF course database as of July 2024. It's likely OSM knows of 99.99..% of all active golf courses and also still retains tags for closed/unused golf courses too. So if OSM were to be inaccurate, it'd likely be inaccurate for whether a golf course is open or closed, rather than OSM not knowing about a golf course existing.

I wonder whether an OSM tile server / custom style sheet for golfers would be easiest and most useful/comprehensive way to keep track of golf courses?

[1] https://wiki.openstreetmap.org/wiki/Tag:golf%3Dhole

[2] https://taginfo.openstreetmap.org/tags/leisure=golf_course#o...

[3] https://assets.randa.org/c42c7bf4-dca7-00ea-4f2e-373223f80f7...

[4] https://thegolfwire.com/worldwide-golf-course-development-re...