I don’t think many of those removals will have any impact on power consumption - at least not unless you’re using them right now. Removing a non-default task switcher (if you don’t use that currently) or theme (e.g. “Plasma Air”) will help with maintainability of the code and more time for other work than hunting down issues in that task switcher or theme, though. This might result in freeing up time to work on other stuff. So, indirectly: it’s possible.