I don't care if anyone has a Xiaomi, Oneplus, Samsung, etc. Each brand is using a modified version of Android, and they chose to be compatible with each other. But for example the "blue vs green bubble" drama is a thing specifically because of Apple locking their unsuspecting users into a closed ecosystem. And it sure isn't Android's fault for not being compatible with it.
The more power a company like this gains, the worse will it be for the whole industry.
I've found the overall performance to be more consistent/better. The "better" part is a bit moot as every time I buy a new phone, the performance should be better than the last one just because it's newer technology.
And while there are a lot of things I don't like, core performance kind of overshadows any other issues I have or features I'm missing out on. Perhaps I should have said "better for my needs" instead of "better product."
A lot of it comes down to software. I had a cpu performance scaling bug that meant my oneplus 7 pro would occasionally take ~5 seconds after unlock to stop being clocked at 100mhz. It made the unlock experience really laggy and crappy. It felt cheap and lazy.