You right-click on the Taskbar and select
Taskbar setting, click on
Taskbar behaviors, at Taskbar alignment select
left.
That's it, the Start button in Windows 11 has moved to the left.
Windows 11 will have some default icons displayed such as: chat, widgets, taskview,... if you don't need these applications you can turn them off to make the Taskbar more compact by: Select Off for all items in Taskbar items and Taskbar corner icons.