The problem is that it may be that none of the drills programmed into the computer is suitable for you.
And the same goes for 500 drills in a book.
The projector does not make Mosconi's ring-around-the-side any easier or faster to set up, and that is a great drill that every student should master to some degree.
The projector doesn't know about the progressive practice drills you have figured out for your own weaknesses until you have programmed them into the system and the projector can't track your progress as well as a penny can.
If having flashy technology gets you to actually pay attention to your practice time, then maybe it's worth it, but in my view the projection systems are not yet fully developed.
Yet, with a projector, once you have it programmed in, you will be exponentially faster in the future.
Take two instructors or two players who are putting in hours upon hours on a table.
The instructor or player with the projector will save literally hundreds of hours over the course of their career with a projector.
Without it, you either have to place donuts or eyeball the locations and place the balls. Vs just pushing a button. And when you’re done with the projector, your table is completely free of donuts or any other such stuff.
And, without a projector, unless you want to do a ton of work, you can’t show a student or yourself the line of travel.
I spend at least 30% of my professional time instructing in shooting disciplines. Be it for recreational/competitive shooters or .mil/le shooters. Pool is extremely similar with fundamentals and training plans.
Arguing that you’re “just as good” without technology such as this is lying to yourself. Can you get to the same place without it? Of course.
But you won’t be as efficient in the long run.