Yeah, generally we already add the modifiers to the roll even when we speak it, so if we say “I rolled 18” it could mean “18 + 0”, “16 + 2”, “19 - 1” etc.
In games like D&D and Pathfinder, it’s pretty much never important what’s on the die without modifiers.
If we do refer to what the die itself shows, we often say “natural” or “nat” in front of it; “That’s a nat 18, so I rolled 20 total”, for example.
In video game terms, nat 20 and nat 1 are critical (success and fail respectively). They (almost) always succeed or fail, so modifiers don’t effect them. Obviously you can’t succeed to fly by flapping your arms or anything that like, but you will successfully flap your arms really well (or on a 1 maybe fall on your face).
Well, in D&D, as well as any other TTRPG I’ve played, players don’t have to roll for obviously trivial tasks like pushing a door open or saying something.
So flapping arms wouldn’t need a skill check.
But yes, in D&D, only the natural 20 and sometimes natural 1 are relevant, so we can talk about them by adding the word “natural” in front of them.
In any other case, the end result including the modifiers matters, so when we say we roll a certain number like 18, we mean after adding in any relevant modifiers.
