I have a UW monitor. The correct position of the taskbar for me is vertical on the right side of the screen. And to occupy as little space as possible, here is how it actually looks

https://i.imgur.com/zhYnnKx.png

I've personally put my monitor on a thick book (about CS foundation, fittingly enough) so that most of the time, I'm naturally looking at the middle of the screen where, incredibly, most of the useful stuff actually is. In any case, for me the start bar is mostly useless.

I think I do mostly look at the top half of the screen, but I somehow reach a different conclusion from you :)

There's nothing interesting on the taskbar, so it makes sense to keep it down there. The most commonly used programs like Firefox, IDE, Slack are pinned to the taskbar, so I can invoke them with Win+[1-3]. When multitasking in full screen, there's Alt+Tab. Overall, I feel like the taskbar doesn't have that much use most of the time, but it's nice to have it on the screen just so I can use it as "shortcut cheatsheet".