With minis, yes. With everything snapped-to-grid, no.
The grid is there just to give us a distance reference and scale, and if you happen to put your mini on the intersection of two lines rather than wihtin a square then so be it, I don't care, and that's where you are. If distance or range matters that much (e.g. are you in or out of the fireball that'll kill you even on a made save) we'll measure it straight-line somehow.
EDIT: noticed after posting the question is posed as specific to the 2024 edition; to me it's edition-agnostic, and I'm answering from a very not-2024-edition point of view.