Originally posted by Weaver:

You don't need to max gear. The initial set for each biome is more than enough to take on the bosses.
The upgrades are there for as an option for people who are struggling to have a way to essentially lower the difficulty of combat by putting more effort into resource gathering.

My maxed iron set was as powerful as an initial silver set, yet I could barely stand two Moder attacks. Unless if you're talking about multiplayer, because in solo, I certainly don't see much option between using or not an upgraded set.