>>42236184Grass is definitely above average defensively.
Weaknesses
>FireCommon STAB and coverage, this is very bad
>IceCommon coverage, pretty bad weakness
>FlyingUncommon STAB
>BugUncommon STAB, U-Turn weakness though
>PoisonKek
That's two bad weaknesses, one middling weakness, one weakness that's okay to have, and then one that barely even counts.
Resistances:
>GroundCommon STAB and coverage move, great resistance
>WaterMost Common STAB, great resistance
>ElectricSomewhat common STAB and coverage, pretty good resistance
>GrassSomewhat common STAB, mediocre resistance to have
Ground and Water resistances easily cover the Ice and Fire weakness. Electric resistance more than makes up for Bug weakness. That leaves Grass resist, which doesn't make up for the Flying weakness, but you can clearly see it's pretty balanced overall in terms of quality. Since resistances are more valuable than weaknesses in this game, it's pretty fair to say Grass is average at the very worst, and it isn't farfetched to say it's good.
OP chart has this incredibly wrong because they just looked at quantity over quality.