Which operating system do you use?

Security issues? who cares about this for end-users. may be network administrator worried about it. I only focus on the compatibility issues of certain industry software. If a program runs well on Windows 7 but is not compatible with Windows 10, then it is also unlikely to be compatible with Windows 8/8.1, so the Windows 8 series has no presence at all.

I am currently using the following operating systems in parallel, but use Windows 11 more scenarios.

Windows Embedded Posready 2009 / Windows Thin PC / Windows 11 IoT Enterprise LTSC at Insider Release Preview Channel

You're right, but I also have Windows 7 for compatibility with older hardware, but I most often use Windows 11 for new hardware.