Trust me, none of the boresight tools are this accurate, and the ones with lasers are the least accurate.
You are entitled to your opinion.
The SiteLite Lasers that I use are actually surprisingly accurate. All that is needed is a clean bore.
I worked with the owner and ceo of that company for a number of years when we were both at Boeing.
He really DOES know what he is doing. Like everything thing else, you do need to tweak it in on paper, but this device will get you there.
AR style rifles and M1A are a piece of cake and you don't have to use a mirror or take the bolt group out.
I have both a red and green one.
Want to put CT grips on your handgun? Mount the grips and grab the green laser. Point at a wall at the range you want to zero. Turn them on and adjust the red point until it is superimposed on the green point and you are done.
When I am done, I remove the laser and reinstall to verify. I like them.
I know some have had issues with the style that fits into the chamber but the products from SiteLite mount in the bore at the muzzle.
I sometimes switch scopes from one rifle to another and the tool helps me restablish zero without going through a bunch of gyrations.
Can you live without them? Sure. You don't have to do that.
Even our local Sportsman Warehouse uses a laser when they mount a scope for a customer in the store.