when imo that shouldn't happen to types
		
		
	 
Honestly speaking, I think this is the issue with the general mentality.
It *should* be like that.
Pokemon is not checkers. It's more like 99D Chess.
Let's take regular chess. In chess, the pawns once they reach the other side can turn into another piece. 99% of the time, that piece will be the Queen or Rook, very very rarely you'd see a pawn turned into a Knight or Bishop. That's because these pieces are significantly better than the other and more valuable to have.
Noone complains that Queen is much stronger than a Bishop, because that is part of how chess plays out.
Pokemon is similar, amongst the various parts, there *is* the type inequality. And despite the type inequality, every type has some kind of good perks that can make it good in the right scenario.
Take Bug. Bug type is definitely not the best, however it does hit supereffectively Grass Dark and Psychic, and the high amount of resists lets it have one of the most busted pivot moves (U-Turn), giving extra value to the pokemon that can afford to run stab U-turn. One of the main quirks of Genesect was specifically how strong its U-Turns hit.
Defensively, surprisingly, Bug type is actually much less bad than people make it, resisting ground and grass while not being weak to ice. Bug/Steel is one of the best defensive type combinations of the game, even better than Grass/Steel.
People also meme how bad ice type is defensively, that on other hand is made up by how insaney strong stab ice moves are, to the point that any time a glass cannon ice type is released, they're almost always insanely strong.
I'll echo 
Yung Dramps . The type chart is fine. Pokemon does *not* need type equality. The massive diversity in how types interact is one of the key components of what makes pokemon pokemon.
Plus, having arguably or situationally bad types gives more creative liberty. You can make a pokemon have insane stats and balance it out by having a terrible typing, and other way around.
We were talking about Fairy types earlier, while I still stand that it doesn't make pokemon inherently op, it isn't false that many pokemon are viable purely due to being X/fairy combined with other trait. Case in point would be Tinkaton and Klefki, two pokemon that are basically carried by their typing that gives them way more switchin opportunities that their stats would otherwise allow.