I'll keep this as brief as possible.
Oxygen OS on the one plus phones have a better operating system.
Reason: more customisability and closer integration with vanilla android os thus the design language is more coherent when using say gboard for example.
Please add third party icons to one ui. No one likes the terrible low effort icon packs in the samsung themes store. Look at what oxygen os does right and work off of that.
Also why is the control panel so cluttered. It was nice and clean in one ui 1, but one ui 2.0 cluttered it with a power button no one needed or uses, we already have a hard key power button.. and who's turning off their phone anyway.
One ui is a nice launcher with nice animations and very high potential but there are still better more coherent launchers that have been around longer.
Give us the ability to change the rows and columns of the control panel back again like we use to have.
Something I thought would be great is live swipeable widgets like ios 14, and the ability to move folders to the bottom of the app drawer leaving the top empty making it closer to the thumbs.. and maybe having the app drawer adapt its length according to the apps in it. So if its only got a few folders have it pop up short.
Also give us widgets on the lockscreen dedicated widgets, i don't want to reach up and swipe through the clock, i want to use the realestate of the screen i paid for.
Thanks for reading!