i saw someone talking about a blackberry-style Android phone the other day with a square screen and people were going nuts for it, even as they were making fun of its huge size. I sort of want one myself, the ruggedness and battery life are an OK trade-off with size and weight.

https://www.unihertz.com/

We have not 'converged on the most useful design'. Equilibrium points are often just the lowest common denominator as a technology matures enough to become commodified. Then you start to see a variety of alternatives optimised for different use cases and market entry becomes more affordable to smaller players.