Today, a lot of 10 users would upgrade to 11 if they could, but their older-but-still-fine hardware is simply being cut off from Windows support.
Technically, a lot of people was also "cut off" for Windows support with Windows 10, however, Windows 10 did not block you from upgrading anyway. Looking at the CPU requirements of Windows 10 1511, the Intel i3/5/7 types all required at least 5000 series or better from around 2015. Newer Windows 10 version cut out some of the 1511 supported CPUs, raising the minimum requirements. I think it was some of the CPUs from Microsoft's own Surface computers, that was kept in the supported list.
Microsoft should just let Windows 11 install with a big fat warning that you are running unsupported hardware, however this could have a negative experience when people run into features that does not work. But most of the way, people would be fine.