A long time ago I was the guinea pig/first user for a company developed system.
I often had my 1 year old at the time son with me when I worked on the weekend. He had a great time smashing buttons on the keyboard and randomly clicking the mouse on the test version. He found most of the bugs.
I have been using custom start menus since the whole win8 full screen disaster. Every time I see the default win 10 or Win 11 menu I cringe. So much crap in the way.
Process optimization reaches a point of diminishing returns. Then if tweaked further it degrades the performance. Microsoft reached the close to the optimal OS design at Win7. It’s all been downhill since then.
The mobile OS systems are reaching the same point. Optimization has occured and most of the “new” additions degrade the user experience.