Mi band - cheap, small, very long battery life
Fitbit - $$, short battery life
Apple Watch - $$$$$ too big, Vert short battery life
Never tried garmin.
So, for everyday I wear mi band.

I switched from Miband 4 to Garmin vivosmart 4. It is smaller and faster charging but battery runs out quickly. Overall for me it is better. It is 5 times more expensive.

I switched from MI band 4 to VivoSmart 4 a few months ago.
Pros: design
Cons: the screen should be turned on automatically in the manner of Apple watch but often it doesnt work, which is quite frustrating. Except that I'm pretty much happy about my new fitness tracker.

I use it for time and stepper mostly.