I have the same experience. The hardware is nice for the price but it's loaded with crappy apps.
Some of them are badly translated, updates to a simple calender app suddenly requires ridiculous permissions.
And worst of all, enabling USB debugging test apps through Android Studio requires a Mi Account. Maybe I'm paranoid but I can't think of a reason other than corporate espionage.
To GP and this: Have you considered the Android One Xiaomi phones? I can't imagine having ads in the default file browser. And a Mi Account for USB debug is just "No".
As with all Android phones (and to a certain extent iOS devices as well), trusting the default operating system is a very bad idea. Unlock the bootloader, flash it with something trustworthy.
The bootloader in Huawei's more recent phones, is not easily unlocked.
The built-in file browser shows ads related to random conversations I've had(not related to searches or my general interests) way to often for me to consider it a coincidence.
I'm seriously considering getting an iphone again, just because I trust Apple a bit more(and only a little).
But there would be no way in hell I would do sensitive work on Huawei or Xiaomi laptop.