Our org recently upgraded to Win 11, and so far my experience with Win 11 has been fine except for this unfathomable change.
I've hade a left taskbar for a couple of decades and find it essential for my productivity at work. I have so many things going on at any given time - numerous apps, PuTTY sessions, docs, mail, etc. The left taskbar enabled me to view a list of my open items, with their name, so I could navigate between them easily. Not having this is really a disaster. I used to use DisplayFusion for multi-monitor left-side taskbars until Windows got good at it, but my org no longer allows people to install third party software so I don't have a fallback any longer.
It's hard to comprehend why this capability was removed, and I sure hope they bring it back. There is no good alternative for working with a lot of open items.