If you need 5k at 27 inches, you need more at 32". But if you're saying that 32" are excessive, I think it's a personal preference. I would never go back to a smaller monitor (from 32) personally - especially as you grow older.
Apparently, ASUS believes there's an addressable market willing to pay a premium for +26.5% color-calibrated ppi in larger form factor.
i'm not suggesting there's no market, i'm just trying to understand why it exists