I had thought about it but I never ended up making something like that because natron does those things pretty good already and you also have BIMP so I never thought it would even have space to be a thing.
The alternative to BIMP on Krita should be Actuator that I wanted to create but then I kinda lost interest into the topic.
But Imagine boards Batch operator is so nice honestly compared to all of them, just dropping things in to work. so less fuss. maybe a thing where you write your python script and the batch operator simply runs it on every single image.
As for the quality loss while reducing I don’t think there is much that can be done with it. It is reducing pixel size so detail will disappear.