Sidenoders tend to run bunker for many reasons
1 is you don't really miss your sidenoder being more impactful in teamfights recently
2 if theyre not, they auto die to thief plus or even worse revenant plus
3 the path of least resistance, if you cant die to the enemy player even tho theyre better than you, you're making yourself way more relevant
4 bunkers recently havent been getting punished for being bad in 2v2s
that being said, alot of DPS sidenoders, typical bruiser ones are much closer to the meta than they were before now, if the balance patches keep coming it wont be long until we see Warrior, Ranger, Ele, and Engi all hopefully on equally footing.