A lot of distributions doesn't support secure boot, or it's difficult to setup, look at the guide to setup secure boot on ArchLinux. A lot of distributions sup

A lot of distributions doesn't support secure boot, or it's difficult to setup, look at the guide to setup secure boot on ArchLinux. A lot of distributions supports secure boot trough generating your CA, using it to sign the bootloader and the kernel and installing it in the UEFI, to do this you need to put the UEFI in "setup mode", that is a mode that permits the OS to add/remove keys, and then put it back in "user mode". Of course not being able to disable secure boot will not allow you to do so. As far as I know the only distributions that supports secure boot without the need to put the firmware in setup mode and install custom keys is Ubuntu, since they bought keys from Microsoft. But that is just as bad as running Windows... You can say, but I can simply turn off secure boot. If the firmware allows it, you can. The problem is if you have a dual boot with Windows: you would need to enable secure boot each time you want to boot into Windows and disable it to boot back into Linux. That is a complication that would make some potential new Linux users just stick with Windows (you have the WSL and you can run all the Linux programs into Windows, why would you need to install it really? That seems to me the policy of Microsoft).