Interesting thoughts given that a lot of very nice sounding gear is designed and manufactured by what are essentially one-man operations - think Vladimir Lamm, Judd Barber, Ken Stevens, Jim White, Ralph Karsten, Kevin Halverson, Steve McCormack, Keith Herron, Emmanuel Go, Wilson Shen, Steve Nugent, Mike Sanders, Joseph Chow, David Belles, and many others. We are fortunate these guys have had passion enough for what they do to share their work with us for many years.
To the question, most tubed gear should be repairable and much of the better solid state gear will last a long time without needing repair. Of the SS gear that fails, I suspect much of it can be repaired by replacing available parts when serviced by a specialized technician. There are guys out there that know this stuff well enough to fix it, but probably not as well as the guys who designed and built it with regards to the sonic trade-offs of using different parts.
To the question, most tubed gear should be repairable and much of the better solid state gear will last a long time without needing repair. Of the SS gear that fails, I suspect much of it can be repaired by replacing available parts when serviced by a specialized technician. There are guys out there that know this stuff well enough to fix it, but probably not as well as the guys who designed and built it with regards to the sonic trade-offs of using different parts.