Black lotus is illegal in tournament play except for Vintage.

Its also restricted there so you can only use 1 per deck!

I play MTG competitively, and if you actually believe this is a thing I'm afraid you have no idea what you are talking about. No competitive game has ever, at any point, worked that way.

From a gameplay perspective, the problem is exactly what your parent said: counterfeit product cannot be used in a sanctioned tournament. Which means most MTG organized play, since even very small in-store tournaments are usually sanctioned events.

This is the plot of the first episode of Yu-Gi-Oh, not a thing that actually happens in real life.