Moto g35 seems to be a decent choice and fits your requirements, near stock UI experience and solid all rounder in terms of specs in this range. We have three motorola budget phones used as daily drivers (Moto g31/g40 fusion/G54), all of them are working fine.
CMF phone 1 around 14k is good. The UI is good & lighter than Xiaomi, BBK, Samsung, etc. Else look at cheaper Moto options, choose at least 6GB RAM. 4GB RAM is too low now.
I would highly recommend Samsung if for ur father… knox + secure update + automation … you can add trigger that allow u to share your father location + even turn internet on (if u ever need smtg like this)