Possibly…but I think some of that depends too on what is meant by “online.” Obviously, if you frequent questionable sites and install unvetted software, that’s a bad idea. OTOH, having a machine with strict firewall rules (so not everything can just phone home), limited outbound access, no daily browsing/email, and only going online occasionally for specific, known downloads is a different situation than using it as a general-purpose internet PC.

Even occasional access to a small number of mainstream, HTTPS-authenticated sites (e.g., major services where the browser can verify certificates) isn’t the same exposure as wide-open browsing. (nb: Firefox’s ESR releases have historically helped extend browser security support on older systems for a while, which can reduce risk somewhat - though obviously not indefinitely.)

Look, I’m not arguing that EOL systems are “safe.” They’re not getting patches. But exposure matters. A mostly appliance-like gaming box that’s segmented and tightly controlled isn’t the same risk profile as someone’s primary web machine.

ICBW and YMMV.

I like linux and I use it (Raspbian, Zorin, Ubuntu, Arch: diff machines). I also enjoy using Win 8.1 on my Lenovo M93p Tiny (8GB ram), as a Playnite appliance / console. This allows me to play emulated games (Wii, Gamecube, PS2, to about 1.5-2x upscale), ~2013ish era AAA titles (Fallout 3, Just Cause 2, Dead Rising 2, GTA IV) and select indy games (like Donut County, Untitled Goose Game, EXO ONE) all from one device.

Normally, the advice would be to use something like Bazzite or Batocera (and I agree!)…but given the hardware limitations and the “it just runs” nature of these older Window games (under windows) I’ve had better experiences sticking to Win 8.1.

YMMV but the “switch to linux cause windows too old” thing has some shades of gray.