analogue market oddities. variable gain vs. fixed

We all know and lots of us think that it's good to have a variable gain phono. Sometimes we will use the lowest gain setting of all possible. Will that mean that we've just paid twice for what we use right now?

On my understanding higher gain phonos give us the possibility to get for the same price lower-output versions and claim to improve the sonic performance of our analogue setups. On the same time, If we use a variable gain phono to increase the gain we a)either turn on an additional amplification stage(s), 2)or step-up transformer(s). In either case we add more harmonic distortions with each step of amplification we bring.
The last described disadvantages will dissapear if the fixed gain phono(with one amlification stage)is used.

That's why I think that phono should be with fixed gain and should be a function of cartridge i.e.

phono = f(particular cartridge) if sonics is on the first place or
phono = f(any cartridge) if convenience is more important than sonics.

Please discuss this analogueaudioscience theorem or formulas and let me know if there is something wrong.