I check all my new lenses as soon as I get them. The reason is simple, if there is a problem, its easiest to find it by using a tool like Focal.
It has nothing to do with obsession, a properly functioning lens is important, and it can be returned and replaced if you check it out immediately. I once bought a used lens, it seemed fine, and after a few weeks, I used it to take photos of my 90 year old father at Christmas. Every one of them was coming out oof. Finally, I spotted that by reviewing them at magnification on the camera LCD. The only other lens I had was a f/4, and in the poor light, I had to use extreme ISO. I lost a lot of photos that could not be replaced, he passed on without another Christmas.
Lesson learned - check new equipment.
How critical is the AFMA adjustment? Most Canon lenses are close enough to where it is not a issue, but there are enough exceptions to make it worth checking. Third party lenses tend to be a lot more variable.
When a lens requires more than about a 5 point adjustment, the improvement is noticeable, and 10 points or more is flat out obvious.
I find, not surprisingly, that used lenses tend to need AFMA more than new ones, but there are exceptions, about 1 in 4 had a adjustment of 8 pts or more.