In terms of Windows 11? You can move the start button back to the lower left corner in the settings, but you can’t stick it to the sides or top of your monitor nor resize it like you could do in previous versions. Even Windows 95 supported all of the above.

The functionality is still there, mind you, and you can do it via registry hacks or third party tools. Microsoft just saw fit to remove the option for the user to do it themselves for some inexplicable reason.