Saysumthinfunnymike
VOTE!!!
It didn't light up, he did that for the sport of it.
Had Hulk kept getting the best of him he probably would have, but he wanted to flex and did just that. You can see initially that the Hulk is stronger than him but once he took those first couple blows he broke him down surgically. Imagine if Bruce was able to learn how to fight from Steve or something and THEN hulk out while retaining what he learned.
That's because while Hulk may be stronger than Thanos in a raw sense, Hulk doesn't have near the fighting ability, he knows how to harness his strength and weaponize it while Hulk is more a brute just destroying shyt