I am using a surface for my art with Krita. It is only me or I have the feeling that with the newest versions of Krita the battery last as much as half as the previous versions.
Has someone run a profiling to see if there are routines running unnecessary that dry the battery?

What is more likely is the opposite: we ran optimizers all year and wrote code to make Krita's brush-tip generation multi-threaded, meaning Krita now makes more use of the resource available to be faster. You should be able to throttle it in the settings.