There is a reason why people prefer Xiaomi over other brands. What I can remember is pricing, ability to unlock without losing warranty, quality of the hardware.

A different phone like Samsung has problems like warranty being void if flashes, bad hardware, riddled with advertisements as you can't use your own firmware because of previous reasons. In fact, many people in my country choose Xiaomi phones over any brand. Also, Xiaomi provides a better ecosystem like distributions of ROM, flashing software officially.

Other phones like one plus, iPhone has a high price compared to Xiaomi.

The unfortunate fact is the competitor of Xiaomi phone is another Chinese branded phone and

Get a XiaoMi, unlock it, install LineagoOS, do not install Google apps ("gapps"), use microG if you absolutely need to use apps dependent on Google services but try to use them first without, many work fine even though they insist on needing Google services. Just like all other phones you'll still have the proprietary radio firmware running on your device which could try to snoop on you. If you want to avoid this risk either get one of the "Linux phones" with discrete radio hardware (not integrated into the SoC, only connected through a serial line, no access to main memory or storage) or get a dumb phone with a removable battery.

Exactly this.

You always have a choice. You can even buy a dumbphone.

If you still buy Xiaomi knowing they spy on you, you just don't care. And that is also a choice.

People should vote with their wallet. This also means you can't always get what you want.