How did you measure this current values? I updated yesterday and have nearly the same feeling. I can watch how the battery drains. But another post told, that after 1-2 days it was much more improved, like a system adaption. But, if this is measurable by screen power consumption this will explain this effect. Also with active AOD I can watch decreasing percent by percent. Will give it a try for some days, otherwise switching back to the 12.5.x.
There are less UI improvements compared to MIUI12, but the system flow feels good in my opinion.