Yeah. It was worse in 3.5 ironically; despite casters having more downsides than 5e, spells were overall stronger. It did leave this narrow window at levels 1 and 2 where martials were basically strictly better, but caster quickly skyrocketted in power, especially if you were playing with prestige classes.
Spell power was reigned in for 5e, and pretty sharply at that (most notably from adding Concentration). But, they also washed away caster downsides, by making cantrips at will, casters not quite so fragile, and by softening Vancian casting. 5e is still absolutely more balanced than 3.5, but that’s not saying a lot; 3.5’s power level was all over the place.
Still, I feel like 5e’s levels 1-5 are pretty balanced, and the martial/caster imbalance doesn’t really become painful until like, level 12.