I had some version of the Redmi 4 or Note 3 for just shy of 4 years before it was lost during an automobile hitting me (a pedestrian). It was fully encrypted running an AOSP ROM at the time so w/e. It was a global variant confirmed to work on (at the time) 3G/LTE bands in my area which I checked with family members' phones who were on AT&T/Cricket. I was using a smaller MVNO with a 10$/mo 1GiB plan but they were also reselling AT&T. Got it from AliExpress, <200$ at the time. I unlocked the bootloader after registering it and going through Xiaomi's website and installed a ROM from XDA Forums.

Then I've used a Redmi Note 9S for the last 3.5-4 years now as well. I bought it on Amazon because I needed something quickly to replace the lost phone. It was ~180$ at the time.

These things are great can't run AAA mobile games I'm sure but I'd never want to do that and they're so cheap compared to everything out there for no real significant benefit to me... The Note 9S I have still has incredible battery life. Shits on the work-provided iPhone SE 3/3rd Gen I have - but that might be security shit they have running because it'll be at 77% battery after checking the lock screen twice and sleeping with it unplugged.

MIUI sucks and has aggressive anti-background activity that can be overridden but updates will add another menu in which something needs to be customized for each background app and reset or require disabling and re-enabling previously set exceptions...