Hi, welcome on board!

Xiaomi phones have a reputation for being great value for money in terms of price to hardware specs and performance, however the software overlay is not everyone's cup of tea. It has plenty of unnecessary apps that you don't need and can't remove without extra effort, some of the stock apps have annoying advertisements and once a while you'll encounter a bug or two here and there. Since you currently use a Pixel, I'm guessing the OnePlus' cleaner and lighter user interface will be more around your wheelhouse, but OnePlus phones don't offer the same value for money proposition that they used to. Best wait and see since the launch of the OnePlus 9 is imminent. If anything, you can get the older OnePlus 8 Pro at a discounted price once the new one launches.