Like I said, ignorance is bliss. How does paying for the same thing twice make it better unless you're getting the profits for the initial, wasted, purchase?
To me, it's a matter of lowering the psychological barrier to investing in a better system.
Sure, if you buy a cheap system and later put it aside in favor of a better system, then arguably that initial expenditure has been wasted. But it's the difference between saying to someone, "Oh, that thing will is junk. Don't waste your money" versus saying, "Well, it's a low cost system, but it is certainly better than nothing, so go ahead and get it if that's all you can afford right now." I long ago decided that it was much better to encourage my neighbors to install a $20 Wyze Cam rather than try to hold them to my own standards and discourage them from doing anything at all.
Some people who buy cheap equipment will graduate to better stuff. Very few of us get into high-end camera systems on an all-or-nothing basis. Certainly I didn't. You start small, and you move up. Maybe later you realize your initial purchase wasn't the best one to make, but that's part of the learning process.