For those not aware, this is a reference to an audience comment at the HL2 E3 2003 presentation: https://www.youtube.com/watch?v=4ddJ1OKV63Q&t=200s

Half-Life 2 was but a twinkle in Valve's eye when the 486 arch was introduced in 1989. ;)

Could maybe run HL1. Maybe.

some og binaries with software rendering would probably slide show it along nicely

Nop, HL1 uses the Quake engine that requires a fast FPU. The minimum CPU for any kind of decent performance is a Pentium.