story for you.
A friend of mine owned the Rolex chrono below which was bought in the 40s by her father and passed down to her. The watch in the early 2000 was in a sorry state and she took it to Rolex for servicing and they refused as the watch was too old and they didn't have parts. I suggested an independent watchmaker who could service the watch and after close to a year the watch came back in superb condition.
So yes we still have capable watchmakers/repairers who can still repair and restiore watches made by the likes of Golay Meylan, Janvier, Berthoud or Leroy.
On the other hand I'm not sure that if you have a Graham, Thompion, Lemania you can actually take it to the eponymous brand to have them
serviced
All this to say that down the line these independet watchmakers are...well ...watchmakers and their watches have been constructed and developed with servicing in mind and all you need down the road is to find a good watchmaker who could service your watch even if its maker/brand is retired, bust or dead.