A mix of too many cooks, I would guess.
The Windows 10 file explorer architecture traces back to the XP one, with several COM extension points, and it got some re-architecture on post vista as they doubled down on using COM for what were originally .NET based ideas for Longhorn.
For example the File/Open common dialog became COM based as well.
On Windows 11, from what I have read they did a full WinUI 3.0 reboot (the migration of UWP COM on top of Win32), losing half of the features in the process.
So far I still consider Windows 11 as the next Vista/Windows 8, and am as eager to update as on those versions.
I've never understood the reasoning of the reorganization that happened in 10, in particular why some things would end up showing twice.
I know in Windows 10 you could remove some of the clutter by editing the registry (which would be helfpully undone by some updates). Don't know if it's still the case in 11.