Based on what? Subjective observation?

Just because majoroty repeat something, it doeant meant that it is true. Conformity behavior shape opinions on observable facts, look at Asch experiments.

https://en.wikipedia.org/wiki/Asch_conformity_experiments

Because bigger screens are more catchy and give you more space to show ads.

True, but if you don't want to give your money to google or use anything from them (why would I need custom ROM?), then your options are quite limited.

What is a common truth?

Anything above 72mm is too big to use it comfortable by one hand or put it in pocket.

I wish there is compact android phone with open bootloadet option.