Just say Micro$oft 
well while there has been some maintenance with X11 mostly also because of Xwayland and some contributor that said “Fuck it I’ll maintain X11 myself” kind of thing. Iirc Wayland still remains as one of the secure Compositors alongside the windows compositor.
But If I would pick between windows and x11, Obviously the latter (security wise).
Linux in general can be plain insecure though considering the filesystem and other things. For sure you can use Fedora (It does some good things like supporting secure boot and enabling SELinux) abd combine Secureblue and stuff like that for more secure linux experience but keep in Mind Secureblue maintains security (hardens linux rather) but not losing so much convenience so some insecurities may be in sight (basically it’s not as secure as say ChromeOS or MacOS) and if you have any questions @RoyalOughtness would be willing to answer but preferably in the thread:
or directly.
I’m gonna say ultimately it is your choice. For me due to using Nvidia and Plain Arch I don’t want to deal with Wayland + Nvidia problems (probably in the next few years before they mature?) so I just use X11 + PulseAudio since I know that they’re at least mature enough that they give me minimal issues. It is ultimately up to you but security wise I would use the new audio server + Wayland (Maybe PulseAudio is fine, not sure if Pulse is like X11 in maintenance but yeah.). Or if I want the maximum security I would just use MacOS (or ChromeOS)