The placement of taskbars (or 'panels', or the equivalent) is always a personal preference. Long-winded explanations may look like a valid justification why some particular preference is chosen, perhaps. But they don't really get to the heart of it, which is that it all boils down to 'personal preference'.
Most of us tend to work 'down the page', especially if we use terminal emulators a lot. In that case, my personal preference is to put the taskbar/panel/whatever at the top of the screen, out of the way, as my work-flow continually moves away from it.
But I stress, once again, that that is purely my personal preference, and my justification of why I have chosen that particular preference.
Windows 7 is the first version of Windows to let you to leave off text from running programs, leaving good sized square icons, so vertical taskbars didn't look as stupid as they did before. I disabled combining taskbar buttons, and tried putting the taskbar on the left. It's been 10 years and I haven't looked back.
Most of us tend to work 'down the page', especially if we use terminal emulators a lot. In that case, my personal preference is to put the taskbar/panel/whatever at the top of the screen, out of the way, as my work-flow continually moves away from it.
But I stress, once again, that that is purely my personal preference, and my justification of why I have chosen that particular preference.