Over the last 30 years (with a big gap) I learned to self service my watches. It is really satisfying. Does make one appreciate the time and effort involved.
A professional will be servicing between 3 or 4 watches a day. There is also overhead to consider.
Predicting the future is problematic. 20 years ago, when my older watch collecting friends passed away I thought watch collecting was dead. My inbox was full of scams and phishing attempts. Huge lots of century old parts were being used for art projects in the steampunk world. (I moved over to pipe organs.) Now the self playing mechanical music collectors who hoarded all the good stuff are at a generational shift.
Now things have swung the other way. At the moment it is a buyers market for things like the OP's example. The information available has settled down. It has become easier to thresh the good from the bad.
I also play around with cameras. What one finds in any collectable is there are windows of opportunity. There used to be big monthly or quarterly doll shows. Same thing applies.
The other thing one finds themselves collecting is information. Be it books, ephemera or links and offline downloads of websites.
Featureless threehanders like the OPs watch do not turn up all that often in the parts assortment listings. This would hint at they are being maintained. Such are what keep the hardware store, estate consignment and mall shops open.
