While ExplorerPatcher can move the taskbar to the left (or right) it does so by first activating the older Windows 10 taskbar (deactivating the newer Windows 11 one) and uses it. The old W10 taskbar could be placed on any edge while the new taskbar can not. It is extremely important to note that very soon Microsoft will be removing the old taskbar (support for it is already dead) entirely. Once this happens apps that rely on it (ExplorerPatcher, StartAllBack, others) will simply stop working. There wont be an old taskbar to use. 

All that said that doesn't mean that it will be impossible to move the new taskbar to the left or right. The reason Start11 can not do it (at least for now) is because it uses the new Taskbar (which is good because that means it will continue working in the future). It may be possible for Stardock to find a means to accomplish the task or it just may be that Microsoft will add support for side docked taskbars in the future.

Just beware that using the other apps you may find one day that they simply dont work at all.

I guess its a matter of personal preference. wide monitors would mean you have further to travel with the cursor to get to the taskbar. I typically use large monitors (47"+) so it can be difficult after a while. Also on wide monitors you have more real estate at the bottom (or top really) for buttons.  If, like me, you have a lot of windows open you need the space. 

Still all that said I would definitely support a taskbar that could be moved to the sides