With ranger being fixed, the fighter is now the weakest class by a large margin. When do you think they will get an update?
Lowest-"Tier," anyway - 'weak,' when you have reasonably high DPR, AC & hps, and can optimize for STR with two extra ASIs, is an unfortunate choice of words.
Probably the fighter will get yet another update in 6th ed, and I can't pretend to be looking forward to it. The record of 'fixing' or 'improving' the fighter is pretty bleak, each edition comes up with something to try to perk the fighter up and make it equal to other classes, but it generally takes away the cool stuff the prior edition gave the fighter with the same objective, or spreads it out to other classes. Other class designs seem to build on prior editions - casting gets easier and easier, more slots, higher relative DCs, etc, etc. The fighter got % STR & rapid attack progression, then the % str is gone, the progression nerfed to itterative, but they get tons of feats, then everyone gets feats and the progression's gone, but they get powers & marking, then the powers & marking are gone, but they get action surge & extra attack... which is kinda full-circle, really.
And, to be fair, the 5e fighter does bear vestiges of prior edition goodies. It gets 2 bonus feats vs the 4 everyone gets rather than 11 bonus feats vs the 7 everyone got in 3rd. It gets Action Surge, Second Wind and up to a half-dozen maneuvers (locked in one sub-class) in place of over 400 powers. It gets Combat Style in place of Weapon Talents, Combat Challenge/Superiority, and weapon specialization. It gets indomitable in place of saves that actually get better with level across the board.