Game Design Why Ele Defs Are A Terrible Mechanic

When implementing a feature into a game, you have to decide if it falls under the umbrella of challenging or annoying. I believe Ele Defs are the latter.
Mobs often have defenses to a certain element or two, often for lore reasons (Fire mobs being resistant to fire etc). However, these defenses don't encourage challenge, and instead just force you to change your build. They do not require skill but time, and it is almost unanimously agreed they are a bad mechanic.
My suggestion: Keep Elemental weaknesses. This way while the game wouldn't force you to keep switching builds, it will reward you for doing so. And make mobs either have defenses in all elements (Looking at you Mr. Eye) or defenses in none, so rainbow/neutral builds will still stat relevant.

 

I don't think they need removing, but I'd be much more fine with elemental defenses on mobs if they were % based rather than raw