Why is solid state more popular when tubes are better?

Yes tubes are more involved and require periodic maintenance. Hybrid tube components need not apply, these are really solid state.

Tubes are better for multiple reasons and yet the world and the trade prefers solid state. Those rare audio shops that are geared toward stereo listening and serious connoisseurs tend to Focus more on tubes.  Those in business who like to improve volumes tend to offer solid state.  All the YouTube channels looking to improve their business tend to be solid state.  Maybe because tubes require much more expertise to sell, and there's lesser and lesser to go around. Solid state is more of a fast food commodity.

Tubes are difficult for businesses due to all the maintenance and complexity so you see it less often. Much much easier to sell hybrids or solid state.




Although I must claim total ignorance, as I didn't past the comment that tubes are warm because they produce harmonic distortion.

@pedroeb To be clear, all amplifiers produce harmonic distortion. In general there are two kinds of harmonic distortion- the lower orders (2nd and 3rd) and the higher orders (5th and above). The lower orders are well-known to be innocuous to the human ear. The higher orders are well-known to be unpleasant if audible. This fact has been known to the audio world for some 90 years or so. If you want a reference see the Radiotron Designer's Handbook, 3rd edition, which was published in the mid to late 1930s. I think its available on CDROM.

The 2nd and 3rd harmonics contribute to what audiophiles call 'warmth'. If not masked, the higher ordered harmonics can cause an amplifier to sound harsh and bright, clinical, sterile and other such audiophile terms.

Tubes are not better.  As a technician/engineer that started my career in the days of mil-spec tubes that you can no longer purchase, I can tell you no Class A tube amp can match solid state for linearity.  They all produce non-linear amplification to one degree or another.  However, some people prefer their sound to have the coloration produced by a non-linear amplifier because the non linear output sounds warmer.  To each their own.  There is no point in buying high end speakers that are relatively linear or neutral if your amplifier is going to introduce non-linear output.

What barjohn said