Took a few years after Windows 11 was released, but FWIW you can now have a taskbar item for each window. It's in the Taskbar Settings -> Taskbar behaviors ->

Took a few years after Windows 11 was released, but FWIW you can now have a taskbar item for each window. It's in the Taskbar Settings -> Taskbar behaviors -> "Combine taskbar buttons and hide labels". I also waited until that was an option, it was a total deal-breaker for me. But it's working quite nicely now.