That's ultra cheap. $94 phone in my country. I won't be expecting a lot at that point.

Not ultra cheap here, $160 for me, but it was indeed in the cheaper category. "Good" phones were ~2x more expensive.

But the thing is: almost all issues are the screwed UI. Makes me wonder what are we paying for in the phones, how expensive is it to sort the UI out?

Checkout this : https://controld.com/free-dns

I'm using Hagezi DNS Pro configuration.

DNS level ad blocking may help controlling a lot of system baked ads and trackers. Spend 30mins or something turning everything off from settings.

This has helped me on almost every kind of phone I've ever bought - I've mostly bought Chinese ones.