It can overcome, but not as competently
Just like with Magic Items, if you do not add feats to the game, non-spellcasters are hit the hardest. Spells are not modified much by magic items or feats, but a Maul strike is.
(I will only consider DPR, other things are very hard to quantify and compare)
Ability Score Improvements are so strong that there are only 4 feats that provide better DPR increases, and those are for special builds only:
- Crossbow Expert
- Sharpshooter
- Polearm Master
- Great Weapon Master
Even Sharpshooter and Great Weapon Master are worse than an ASI most of the time, unless you have access to near constant advantage.
As long as you can improve your main stat, you are not much behind feat users.
Unfortunately a standard Fighter with a 16 in Strength maxes out his Strength at level 6; after that you will really feel the difference.
Conclusion
Until level 6 you are fine, later you fall behind. At level 12 you are about 60%* as effective. After that the gap remains the same, as there are not many great feats, so the third feat of a Fighter is most likely not much better than an ASI in a secondary stat.
How much stronger are you with feats
Imagine a standard HalfOrc Fighter at level 12, optimized for damage output:
Starting abilities: Str 16, Dex 10, Con 16, Int 12, Wis 13, Cha 8
Fighting Style: Great Weapon
With feats, Str becomes 20, and takes Polearm Master and GWM.
Attack: +9 (Str 5, Prof 4)
Damage: 3 x (1d10 + 5) + 1d4 + 5 = 41.9 (with Great Weapon Style)
DPR against AC 18: 0.6 * 41.9 = 25.14
DPR against AC 18 with Advantage: 0.84 * 41.9 = 35.2
DPR against AC 18 with Advantage and GWM: 0.58 * 41.9 = 47.3
Without feats, Str becomes 20, and the rest does not matter for DPR.
Attack: +9 (Str 5, Prof 4)
Damage: 3 x (2d6 + 5) = 40 (with Great Weapon Style)
DPR against AC 18: 0.6 * 40 = 24
DPR against AC 18 with Advantage: 0.84 * 40 = 33.6
*Getting Advantage is trivial at level 12 between spells, maneuvers and feats (Shield Master), so comparing the best values it is 47.3 vs 33.6, 40% higher with feats.
Paladins and Barbarians experience an even bigger difference, Polearm Master adds about 50% to their damage, while Fighters have 3 attacks at this level anyway, so it adds about 33%.