Actually, this isn't the true Point Blank Range method at all. That requires zeroing at a specific distance, determined from charts or apps, that will allow shooting to some other specific maximum distance without having the bullet rise or fall more than a specified amount above the line of sight. You might be required to sight in at 178 yards, giving you a Point Blank range of (for example) 314 yards on a target with a 6-inch diameter vital area. The actual numbers would vary based upon not only your ammunition but also the size of the game being shot. It works and is simple enough, although a bit cumbersome to set it up; never liked it myself.
Sighting at 100 yards is in no way superior for shooting at game at the ranges the OP mentions. If you sight in at 100, the only way you will get "wayyyy better" overall accuracy is if you actually hold over at 200, 300 and other yardages, or dial with your scope. Dialing a scope makes sense for long range shooters, but for a guy to be fiddling with his scope because the deer is at 250 and he is zeroed for 100 is just silly. Holding over is a bit faster and easier, but if you are doing that then you might as well just zero at 200 and avoid all the drama and complication.
Most of my hunting guns are zeroed at 200; easy enough to hold under an inch or so at 100 or a few inches at 300 if you really want to, but for game the size of deer it's unnecessary. If you think that you might shoot much further than that, you need to determine...by actual shooting, not by asking your phone...how much holdover is necessary. And if...big if... you decide at a later date that you want to move into the world of exposed turrets and/or complicated multi-zero scopes, you can always do so.
Dialing scopes and/or using Christmas-tree reticles are techniques that are useful and appropriate for long range shooting, but simply add unnecessary complexity to short ranges that most hunters...like the OP...will be engaged in. I recall one of those Bubba-goes-hunting TV shows in which the hero was sitting in a tree overlooking a bear bait at close range. A bear showed up, and the guy then began to dial his giant baseball-bat-sized scope down to its minimum focus distance and magnification before raising his 1000-yard gun for the shot. While this is more extreme than a deer at 200 or 300 yards...the principle is the same.
Don't be that guy. If you're hunting and shooting at 200 or 300 yards, use techniques that were developed and designed to optimize and simplify shooting at those ranges...rather than stuff intended for 3x, 4x or 5x those distances.