Question about tubes in the old days

In the old days, It was common to take your tubes into the electronics store where they had a large, floor standing, tube tester out on the floor for you to use. So most people just tested their own tubes, once a year, or when perfomance seemed to lag. Believe it or not, repair persons would also come to your house to work on your electronics and would check and replace tubes as needed in the process.

Many older circuits used tube rectification, which is less common today, and a lot easier on tubes than SS rectification, all things being equal. Some designs, both then and now, biased the tubes hotter and those designs yield shorter tube life spans.

Many tube amps did not have adjustable bias voltage. The tubes were "self biased". This means less power amd/or more distortion, but it did mean a lot less fussy work.
Tubes seemed to last forever. I once had a Heathkit amp where the output tubes pulsated with a blue glow in time with the music, but I didn't replace the tubes. It was cool.

When I was in high school (70's) I had a Dynaco SCA-35 integrated amp...about 17 watts/side using EL-84 tubes. I listened to that thing for hours on end. I never replaced a tube. When I went to college I moved to a Pioneer solid state receiver. Fast forward many years....I figure that tubes are pretty cool again. I go home and find that old integrated amp stashed away. I plug it in. Wonderful sound from all the original tubes. My experience would suggest that old gear and old European tubes lasted a long time.