Sure.And there isn't a car which doesn't need fuel. Which doesn't mean that fuel efficiency should be ignored or that a car that goes one mile to the gallon is acceptable. 5e is far worse than its immediate predecessor at this. Or for that matter oD&D.
4e by level 30 I can provide a 20x ratio of damage output between naive and optimized characters, near complete immunity to damage by any published monster, almost perfect shutdown of almost every monster visible in an encounter, and other stuff.
Pre-essentials 4e prescribes how magic items are distributed, and leaves no tools here short of artifacts with enough scope to balance it.
I cannot produce infinite simulacrum wish chains in 4e. You can get close. But the combat engine? The 5e combat engine and the 4e combat engine are not that much different in over optimization issues.
In under optimization, in my experience 5e is better than 4e; a default, unopimized 5e character is closer to a reasonable baseline in 5e than it was in 4e by late game. There are exceptions (Ranger is a big one, or Warlock who never gets around to taking AB).
Unopimized 4e characters made level 30 4e nearly unplayable. Lack of DPS would make any challenging 4e monster take forever to kill; if you had monsters that died fast enough, their damage output would be anemic against unoptimized 4e characters.
Part of this is the reduced number of customization points in 5e. In 4e, a level 30 PC has close to 30 Player-chosen customization points, and often finding one that is 10% better than an unoptimized one is usually possible. 1.1^30 is 17x more effective, and it happens when building 4e characters.
(In 4e, you have 18 feats. If each feat adds ~3 damage per tap that is ~54 damage per tap. Then you go for high-tap powers, damage-per-tap items, extra-tap items and paths/destinies, etc. A feat that ups your damage by 3 isn't a top notch feat that breaks the game (weapon focus for example), but if you can find 18 feats that are that good (or do something equally good) you diverge away from the baseline.)
In 5e, you have 5 ASI/feats and 1 subclass pick; few other choices "stack" like they do in 4e (even spell picks). Doing stuff like multiclassing can expand this (which is why MC is important for optimization; it isn't that MC is powerful, it is just that it gives more things to optimize).
Now, I've played a 5e character that is optimized next to an unoptimized ranger, and the ranger did have issues. But next to a relatively unoptimized fighter? Far less of a problem. And it wasn't hard for the DM to fix the gap.
I've seen the same problem in 4e, and by paragon (teen levels) the unoptimized character (barbarian) was unusable.