Over the past few years it has updated and installed new bloatware multiple times and even re-enabled Facebook background services.
You'll need to check if your snapdragon or exynos for compatability.
It gets you the latest version of android (since samsung decided that 2 years is all they're willing to support their flagship phone for) and a complete lack of bloatware.
I'll add that some apps (noteably netflix and banking) can throw a hissy fit on rooted phones and you will have to use something like Magisk to get the app store to function correctly and allow you to download the apps.
Xiaomi phones have a waiting period, you are required to log in with a Mi account then use the phone connected to the internet for 7 days to be able to unlock it.
Samsung here seems way more user friendly. And with Treble GSI ROMs, you can flash a custom OS on any phone, except Samsung has less problems on average with the kernel (ignoring their security features) compared to Xiaomi which requires a custom kernel in many cases to enen boot a GSI.
Yes. I do know that. Even I use a custom rom on a redmi phone
Not consistently and many don't have much support in the ROM market anymore.
Plus, the devices are pretty much just worse than Xiaomi's, so they don't get much attention from the ROM scene.
That's almost everyone. Yesterday, I opened a brand new budget samsung phone. Despite not logging in anything and declining every box I could, it was automatically filled with invasive apps. It came with made in India sticker.
At least with xiaomi, I can flash it with a custom rom and remove the bloatware. Many alternatives lock down their phone.
The other phones that I would trust are expensive and out of reach for many Indians such as the pixel (their last device was banned in India).