Fighters in 5e basically come with a handful of builds that you could have made in 3.5. Eldritch Knight, Battlemaster, etc. In 3.5 you could have done countless different things but now you are restricted to a set of binary choices, but I digress.
Fighters can cast spells and hit things, or be the best at hitting things, like no one ever was, to hit things is his real test, to hit them is his cause. What more do you want? It's fighter from DnD. Not complicated NOR SHOULD IT BE.
