An interesting aspect with Dungeons & Dragons games is that there is an entire sub-culture dedicated to discussing the min/max and meta of classes and characters in the game...
...which leads to the question, what class is the weakest/strongest in the game?
A recent discussion I was a part of had the fighter as the *weakest* class, when compared over the entire level/life cycle of the game. Early on, levels 1-3 the fighter (class, Barbarians, etc.) is the strongest based on damage and hit points- having the most hit points of the classes and damage output compared to the other characters, but as the game progresses and the group levels up, the fighter gets left behind.
Compare what a fighter can do at higher levels vs. an arcane class, divine classes, or even stealth classes- even the out-of-place monk can slap a fighter around? Really? I of course disagreed. So MUCH depends on play style.
When you just compare character sheet to character sheet, these are numbers and stats that exist on paper- not in real time. Without even min/maxing I could build a fighter that could kill an arcane class in two-three hits.
The strengths of the fighter need to be understood. Hit points give you the staying power to out-last damage. Damage output when combined with good ability scores, correctly leveled magic items, and feats- if your Dungeon Master is using them, makes the fighter very powerful. BUT. You have to get up there to make base to base so you can swing away. At the higher levels mobility is the win/lose of the fighter.
One needs a way to fly/levitate/teleport or move at X4 speed so within one turn you can be right in front of what you need to hit.
The fighter also needs the classic Greenstone Amulet defense- some sort of magic protection to resist and throw up some dice against charm and hold spells. Properly sourced, a high level fighter is QUITE potent I assure you.
Get in the game, and not the paper.