Philosophy in blender -- whew that's a topic! We can all wish it had stayed monolithic but there are multiple, like overlapping waves holding onto vestiges of previous eras.

Left click versus right click select was a real war and to some degree, minor skirmishes are still being fought. If you really and truly want to learn to 'go with the flow', realize that the 'default' hotkeys are not the real 'default' hotkeys for blender veterans and that it was fairly recent when the program defaults got switched over to be noob compatible.