Land-based strategies are inherently strong in this environment, and Golos is one of the best land-based things you can be doing
Green is also exceptional at creating an immense mana advantage, typically with cheap cards like mana dorks (Llanowar Elves, Badgermole Cub) and land-based ramp, which is pretty unique to green (Rampant Growth, Cultivate)
It seems unlikely that a bigger Grixis deck could emerge, as it's hard to imagine how it wouldn't just be a worse version of Shadow
Its also in one of my fondest memoriesin which my opponent killed me with commander damage with Zedruu the Greathearted after a few jumps with Elspeth
It enters the battlefield with six 1/1 counters, so for two colorless, one black and one green, youre getting bang for your mana