I was thinking about this today. At what point will vacuum tubes go the way of the dinosaur like film cameras or analog audio tape. I sure hope not anytime soon let me first off say.
I wonder, even with die hard photographers and film makers extolling the virtues and artistic merits of film they still lost the battle. Same with recording engineers, producers, and musicians and tape. At some point I wonder if the amp manufacturers will decide that digital is the only way to go and stop putting tubes/valves in their amps.
Was playing my tube amp and enjoying it greatly and like all things I realized how fleeting it may be like so many things. These things I ponder as I get older.