Like a fox!
I do agree with you that microsoft software is very much "Imperfect". However that does not change the fact that if people want to actually use the Microsoft Windows operating system they must leave dot-net installed. I outlined above how to kill the background processes for dot-net which effects the performance of games and any other running software. As to start up times that's largely irrelevant because most people are at least on a modern SATA 6 Gbps SSD on computers with 6 Gbps SATA controllers which complete the entire cold boot start up to desktop in < 30 seconds (even with Dot-net installed). NVME drives are becoming far more common today however which are even faster than SATA Drives. Having dot-net installed is irrelevant to system start up times in 2021 as most people have computers at least made within the past 5 years. I would remind you that you are in the extreme minority with your computer. Typically most people do not still use 14 year old hardware today for their main computer. I would suggest that you think of this when writing your posts. Just because something being installed makes your computer start up slower does not mean that it will effect everyone else.We are both positively thinking people, but at my personality it dominates the side of troubleshooter and problem solving at any cost, or else I do not get paid.
This Link, it might help you to understand that regular computer users, they do suffer when MS this delivers imperfect software.