I will have to think hard about this one.
My 1st thought is if you tune the guitar down a step and then put a capo on, the strings would be as tight as before and just as hard to fret as before you tuned it down.
I am probably wrong.
I don't like telling folk they're wrong, so lets just say there's a concept that you haven't quite got hold of yet.
If you pick up your guitar, and a change in temperature has made all the strings flat, you won't know unless you compare your tuning to something else like another guitar or a tuner. So you play away quite unaware that you aren't actually playing pure, accurate notes. No problem. As long as the strings are in tune with each other you never need to know if they match the sounds suggested by your tuner. You form chords and pick and strum and learn just the same as if the instrument was in perfect tune. But. The strings have to be in tune to each other. (It's tuning by ear. If you can't tune this way yet, then that's something to achieve.)
The only time this can be a problem is when you play in company with someone else, like your teacher for example, or maybe a friend who's come over for a jam session. Then the guitars have to sound the same. Or if you're a purist trying to learn "perfect pitch" then you'll want to always be spot on. Most of us aren't.
Strings make sounds (oh boy, is that simplified!) according to how tight they are, and how long they are. Even a loose string, if you fret it up the neck, will sound higher, but the tension of the string remains loose. The capo trick is a great way to help sore fingers or the move the playing to where the frets are closer together so your hands don't have to stretch as much.
However you tune is up to you, and no-one else will even need to know why. Just make sure all the strings are in tune relative to each other.