Not exactly. There's some minority of customers fooled by that pricing, and that minority is driving that pricing scheme.
The restaurants chose to diverge from the underlying pricing, knowing that there was a risk that people would catch on, or the underlying economics would change.
I'd note that some have given up on it because it stopped working. McDonnalds just charges $1 for any drink, because the customers came to understand it was overpriced, and learned to work around their pricing shenanigans.
The goal of the pricing scheme is to deceive people into thinking they can get their meal cheaply, as the main meal is cheap, and what's advertised. It's 100% about tricking a minority of customers. That's the entire idea.
The restaurants chose to diverge from the underlying pricing, knowing that there was a risk that people would catch on, or the underlying economics would change.
I'd note that some have given up on it because it stopped working. McDonnalds just charges $1 for any drink, because the customers came to understand it was overpriced, and learned to work around their pricing shenanigans.