My first amplifier was a Heathkit with vacuum tubes. I took it to the free McIntosh amplifier clinic where they measured 25% distortion until I replaced the output tubes then the distortion dropped to 0.5%. The tubes became mismatched about every 3 months so I replaced them often.
The high end stereo parts store near me sells very expensive solid state amplifiers with vacuum tubes glowing on top. The tubes are for show and are not in the amplifier circuit. I think they even have CD players with vacuum tubes.