Anyone who thinks watches are "dying" I can pretty safely say doesn't know much about the current market.
Wristwatches now are HOT, and a lot of them(vintage and modern) are being bought by guys my age(early to mid 30s). I don't see prices coming down any time soon.
Aside from that, I've seen more people my age drawn into "nice" watches by the Apple watch and other "wearable tech."
Fashion brands are not going to hold their value, but I'd expand your list to more than 4 brands that will hold their value. Rolex is at the top of the list. Patek is certainly there, and in fact you can't even get on the list to BUY the more prestigious Pateks(complications namely) without building a "portfolio" of lower end Pateks. Omegas always have the name recognition and timeless design. A. Lange, Chopard, JLC, and probably a few others I don't see losing value any time soon.
In general, luxury goods are HOT now, and as (I think it was you) said earlier in the thread Rolex sells everything they make now.
Also, I find it funny that people here and elsewhere also seem to say they don't "get" buying expensive watches. Some people appreciate high quality goods, and there's a lot of fine manufacturing and engineering that goes into these pieces. They are true marvels. I'd suggest people who don't "get" it just be content with functional inexpensive pieces and let those of us who like nicer watches enjoy our hobby.