Across the board, in product survey after product survey, consumers agree with you every time about thin phones. At best nobody cares beyond being briefly conceptually impressed (in a way that doesn’t translate into sales), at worst people actively hate how fragile it looks (or actually is). They always would rather have more battery life than a thinner phone, and actually below a certain weight most consumers prefer a phone to be heavier.

So why do companies keep racing to make the thinnest phones?

I honestly have no idea. This isn’t one of those things where I pose a rhetorical question and then answer it. The planned obsolescence of the battery seems plausible, but a thinner battery doesn’t really correspond to a shorter lifespan, just a shorter duty cycle. Maybe it’s just a vanity thing, like a competition between companies, but the bean-counters don’t usually let that sort of thing keep going if it doesn’t sell. Maybe it’s marketing, but that never really succeeds either. I really don’t know.