I agree. I suppose all of this recapping and rebuilding won’t hurt anything, but it gets expensive fast and you never know if it would have worked fine for years without it. Also, I talked to a pretty good tech and he said he gets a lot of business fixing things that were given “complete rebuilds”. He said a lot of time it is slipshod work that just makes things worse.
I will say, in my limited experience some of the old transistors are more problematic than the old caps. I had this issue with my Kenwood KA-7002 amp. It was working fine but suddenly degenerated into an awful mess of crackling and popping. It turned out that there were a bunch of bad transistors. I got it fixed but it was expensive because the thing isn’t easy to work on either.
I could have known this in advance of buying it if I had read up on it in the audiokarma forums. It is a well known problem and there are lots of discussions about it. I recommend searching there for any specific model of anything you are considering buying so you can read up on the good, the bad, the potential problems and how they can be fixed, and ideally restoration threads if they are available.