There are some people who suggest that the type chart needs an overhaul, because some types are used less, outclassed by other types, or are generally given bad stat spreads. Here are the types who have suffered from these categories:
Grass types - They have 5 weaknesses, which ruins their supporting roles, and suffer from shallow movepools to cover them. Very few of them have a Rock move to cover 4/5 of their weaknesses.
Fire types - They have a glass cannon status, and to make matters worse, they're next to unusable due to the presence of Stealth Rock. Solarbeam is also a terrible way to cover their only weaknesses if you're not using a Sunny Day team. Dragon types outclass Fire types, for they also have access to Fire moves to beat Steel types.
Electric types - Despite having only one weakness, Ground, they have a fragile speedster status, which means just about any move they don't resist can be a OHKO. They also suffer coverage against their only weakness.
Ice types - They only have one resistance, which is their own type, and that's about it. Game Freak constantly tries to make them bulky to make up for it, but that's not how the type itself works. They are outclassed by Water types, who also learn Ice moves, have more resistances, and do not suffer from a Stealth Rock weakness.
Poison types - They only have one advantage against Grass, which isn't a very common type in battle, and it lost its niche by the fact that every single Pokemon can learn Toxic.
Psychic types - The real reason why Psychics were OP in Gen 1 was because of the lack of diversity and strong moves for Ghost and Bug types, and most of the Kanto Pokemon were Poison types. Apart from legendaries, Alakazam was the strongest Gen 1 Psychic type while everyone else have lots of weaknesses and don't have powerful special stats. Since then, GF has been screwing the type by making slower and weaker Pokemon.
Rock types - Because of how dominant Fighting types are this gen, they can't utilize their full potential. Plus, they can't cover all of their 5 weaknesses unlike Grass types.
Flying types - Despite Fighting types' dominance, Flying types are rare to be seen due to the fact that not all of them have good SpA stats to use Heat Wave against Steel types, nor do they have good Fighting moves. Some aren't bulky enough to be worth using despite getting harmed by Stealth Rock.
Which of these types I've listed do you think have suffered the most in the series?