Yes, the tube amps inherently deliver generous amounts of 2nd order harmonic distortion. They just lack the balls to drive big-ass speakers. I went to Atlanta one year to hear some Klipsch theater speakers that were 105db eff. And the guy had a tube amp driving them, so after his demo song I asked him, " is this all they can deliver ? The percussion is not chest thumping". He said well I can switch it out to a SS amp and we can see what happens, after the replay he stated he was going to be selling it as he realized it just didn't have the umph .
I apologize for getting a little off topic but I had a Crown Macro Reference amplifier that had a damping factor >20,000 from 10-200hz and 1800 @1000hz and delivered 1500 watts/ch @ 2 ohms stereo. Talk about a great amp to drive subs with.
Stereohile article-
https://www.stereophile.com/solidpoweramps/1292crown/index.html
My big Audio Research SP-12C tube preamp was glorious sounding, but probably the best sounding was my SS Classe CP-35 Preamp, should have never sold that one. I have always tried not to romanticize about certain kinds of gear like tubes and horns, but have owned the Holy Grails like the 1943 RCA Ubangi bass cabinet with (2) 15" field coil drivers at 105db eff. And weighing 535lbs, 8ft long. Along with the matching Western Electric tube amps.