There is an increasing amount of slide/zoom/fade type animations appearing in the plasmoids. ('Sytem Tray Settings' for example now 'slides' when selecting between 'General', 'Entries', and 'Keyboard Shortcuts'. The calendar plasmoid uses a 'zoom/fade' when navigating... etc. etc.).

Whilst this may look good on the likes of a touch screen tablet I personally find it very unpleasant on a desktop used for work/business. Subjectively it gives the appearance of slowing down the system, and, IMO is distracting and, I'm sorry to say, rather childish.

Please, let there be an option to disable it.

OK guys. I guess you all just love animation

Found a solution, of sorts...

Adding:

[Units]
longDuration=0

to ~/.config/plasmarc

gives 'instant' animation... (would be much better if there was simply a global option to disable.)

Thank you for posting the solution.
I had figured out how to disable animations everywhere except the task manager bar and thought it might be impossible before finding your post.

Or just go to System Settings -> Workspace -> Workspace Behavior -> Desktop Effects and enable/disable/configure whatever you like