I cannot believe this is a "deliberate design choice". Clearly there are people annoyed enough to look for a solution to the inflexibility of the taskbar, and it is my experience that the vast majority just accept inconveniences quietly. I've heard of work arounds, and I am likely technically capable enough to implement them, but there are plenty of people who are not. Furthermore, I shouldn't have to "tinker under the hood" to make my screen the way I like it. I like my taskbar on the side because I find it easier to see the screen when my vertical work space is maximized.
Honestly, I find it a bit "lazy" on Microsoft's part to not make the taskbar on Windows 11 as flexible as it has been on numerous prior Microsoft operating systems. I "upgraded" and then reverted back to Windows 10 when I found this "feature". Now I am putting off "upgrading" to Windows 11 as long as I can on my existing computer, despite constant "nagging" by Windows updater, and I am putting off getting a new computer which would likely come with the dreaded Windows 11. I hope Microsoft reconsiders this "deliberate design choice" and gives us flexibility of our taskbar!