Never go for 3/32 variant in this age. Phone becomes super slow with all those custom skins. My dad's Redmi has become so slow after new miui update. Ideally go with 6/128 gb variant to have a safety net for next 2 years.
My primary phone died 2 weeks before and couldn't find a good option to upgrade to(bought OP Nord CE and returned it the next day).
I had a Redmi Note 3(2G/16G) lying around. It came with Android 5.1 and at that time it was swift to use. The last update for it was in 2019 IIRC, but at that time the device was unable to be even as a calling phone. UI used to be very laggy and constantly ran out of ram. The most memory-hogging thing was Google services. Flashed AOSP 10 based custom ROM and with Core package of NikGapps.
Tada! It's usable once again.
The problem with modern software is that it's designed to be run on much higher specced hardware than our average mid-range smartphone. The added gain by running this modern(hogging) software is minimal.
I had bought Nokia 3.2 phones for my mom and aunt around 1.5 years ago for around 8k each... they are currently updated to android 11 which surprised me. I doubt they will get a12 but should get security updates for maybe another year.
Caveats are it only has 2.4 ghz wifi and 720p screen but it's sufficient for their usage which is mainly WhatsApp
I have an elderly aunt in my building who used to run with 8gb storage on some Moto phone on A 8.1. Brought it to me for debugging. The phone wouldn't allow me to use for 1 second with Memory low status. Casual use, WA. Told her to get a new phone.
Yes 32 GB variants run out of space quickly. Even basic apps like FB, Whatsapp use a lot of storage if not monitored regularly. Parents and elders receive lot of nonsense posts in social media groups which they never bother to delete and storage gets full quickly.
Test various Mi apps like mivideo, mibrowser, mimusic etc. to ensure no full screen ads. Also try installing apps from play store, folder renaming for ads, notifications.
Hope you have removed getapps.