A used GL502VT could be an upgraded Win8.x if it was sold before 29 July 2015.

WinVer might (or might not) report if it's been "upgraded" to Win10. But the Windows Update history/log would definitely contain KB3035583 (the GWX invitation) installed sometime between 29 July 2015 and 29 July 2016 (or perhaps even 31 Dec 2017 on a select few devices). This update would of course never be offered (and cannot even be installed) on a "pure" Win10 system.

and whyyyy would you want to go anywhere near windows 8?*

I can understand wanting a "clean" Win10 install vs an "upgraded" Win10 install. Patched, upgraded, and migrated operating systems are always more bloaty and less reliable than factory operating systems, especially after being used (and misused, and even abused) by any previous owner(s).

And some people still prefer Win8 (or even Win7) over Win10 for whatever reasons. Plenty of threads already exist which compare and argue over WinOS differences.

But the fact is that the ASUS support/downloads page for GL502VT currently offers only Win10 drivers. GL502VT-specific drivers for other (earlier-Windows or non-Windows) operating systems will have to be obtained from elsewhere, if they exist at all. Like it or not, Win10 seems like the "best" choice for this laptop.

ill give you another reason, DX12.