IMPORTANT: If you scope has Parallax adjustment on it, not matter how high end, the settings may not be right for real target focus. You may have to set it for 150 yds at 100, or 75 yards at 100 yard target.
The newer type side Knob type is the Parallax. The Front Parallax is the same in a different location, once you learn to ignore the distance and get the target clear, a lot of cross hair issues are gone.
Look at your target, turn that front or side focus until the target is clear, then your cross hairs will work right (mostly, some may have issues with some cross hair or dot)
The difference is that the ocular is the reticle/cross hair/dot focus and the Parallax is the target focus. Get the Parallax first then the cross hairs/dot.
The cross hair /dot focus may change a bit depending on the lighting conditions and need adjusting. Not an issue on thick cross hairs (my experience)
You need to break this down in some logical groupings.
What I do know is my eyes do not like some scopes (Leupold included). Something about the cross hairs just don't focus right.
That said, a higher end scope gives you much clearer clarity. As noted by others, there are sleepers out there.
Hunting: 3-9 and good solid cross hairs. I have put two Redfield Revolution scopes on the family hunting guns. Solid. But they are NOT target scopes.
Target Shooting: Dilemma city. You want thin cross hairs or (better for me) a dot. You don't want the cross hairs to disappear.
I have two true target scopes.
NightForce: That is the best one, 8-32 with a dot. I can sight on a 3/8 circle at 100 yard with it (the dot is like 1/8 MOA. Its parallax is not accurate, once I figured that out (learned from reading) its been stellar as the dot is clear (yes I have to adjust the ocular to make the dot clear)
I do not go full magnification, 18 works with that scope as its so clear.
Cabella's: My sleeper, 6-20 power, 1/8 inch clicks, a bit busy reticle but easily sees the 1/2 inch clear inside (black border) target squares. I can use the vertical dots on the 3/8 Rounds.