I beg to differ!
"IF" your reticle isn't "level", bullet impact will change 2 directions with one simple scope adjustment! Maybe not alot, but "enough"!
I have (IIRC!) a set of "Wheeler" scope levels.
One clamps to the barrel. The other sits atop your elevation turret!
AND......
just as sure as people have different eye colors, we each have different perceptions of up, down, left, right and depth perception.
Jim could see a deer across a peanut field and tell you the range within 20 yards, give or take!
Me?
I was doing good to see the deer, much I less "guess" the range! LOL!