That sucks. I'm on the NE version. Is yours the original? Have you tried a factory reset? I don't debloat as sometimes it can cause problems. 30% must be caning your battery. Are you sure it's not a rogue app?
Original 5G with 780 SoC, it's completely debloated and i did factory reset as well, had no luck. No other app is draining my battery, only Android System, dunno what it is, pretty much tried everything, i am pretty sure it is software problem...
Just the processor difference, Snapdragon 778 for 11 Lite 5G and 732G for 11 Lite because of the 5G network added and storage increase to 128 for 11 Lite 5G 6GB Ram phone.
But to be fair, the NE version was released in October, 2 days before official Android 12 is out. So by the time most people receive the phone, it is already 1 version behind. So it really deserve 3 major updates (not saying Xiaomi will stay true to their words though)
I have root. Just install magisk, patch boot img (extracted from rom d/load), then after enabling usb-debugging, fastboot flash boot patched-image-file.img. And Titanium Backup is most useful for most people imo
I had the same problem. I realized it was because of an app, in my case Notify Buddy. It kept the phone awake, so it appeared like Android System was the cause of draining. But as soon as I removed the auto start permission from that app everything was back to normal. So try and remove the auto start permission from your apps, one by one, and see if it gets better.