Avengers: Infinity War - 10 MCU Heroes Strong Enough To Face Thanos
What Groot lacks in intelligence (and he lacks a lot of intelligence) he makes up for in raw brute strength and incredible durability.
Yes, he's not a skilled fighter or a master tactician, but he's not afraid to get his hands dirty, and when he does let loose, the results can be devastating.
He can grow his limbs to enormous lengths and use them to whack (or impale) people out of arms reach, he can eat a ton of bullets without sustaining any major damage, he can shield his teammates by encasing them in wood or by using his own body as a barrier, and... he can light up a dark room. Useful.
We know he's powerful then, but how will he hold up in Infinity War? As we already mentioned, Groot isn't the smartest of life-forms, so at best, he'll prove an annoying distraction for Thanos - a distraction that will be very hard to shake.
Groot could snake his branches around Thanos and hold him up temporarily, or turn himself into a wooden barricade, buying the Avengers more time should they need it. He can also soak up a lot of damage and even if Thanos gives him a good beating - or destroys him completely - he can grow himself back, as long as there's something left to grow back from.
This means he can throw himself into harms way without thinking about the consequences, which could help him save another hero's life.