There hasn't been much of anything that I have ever kept past 10 years or so. The one exception that I can offer is a Carver C-9 Sonic Hologram unit. I only say that because I can switch it in or out of my system. Also, when I own any electronics of that age, changing out electrolytic capacitors is a given! Likely the RCA jacks a close second. Yes folks, caps do age and will eventually cause some sort of trouble. Having said that, I believe there are numerous products made back then that simply slipped through the cracks or out of favor as new ideas came to be. Quad and HT were murderers to a host of already good gear at the time. Then there were victims of one hit wonders>> Sony's El Cassette or digital tape decks never had a chance to make much of an impression.
How long do you or should you keep your gear.
Another interesting article and may spark, debate, reflection, envy?
I think I have jumped off the proverbial rodent exercise wheel for now.....wait I just read about that DAC..
For your enjoyment and Happy Holidays.