> Retail traders that started "investing" in the last two years have been trained to believe that stock splits means a bunch of money will pile in because the price looks cheaper

I have heard this exact thing debated since the late 80's, so I'm not sure what the last two years has to do with it. The fact is, whether there's a real effect there or not depends less on the precise math of the situation and a whole lot of behavioral and psychological factors. Splits goosing the stock price is a real thing that happens. It may be entirely self-perpetuating crowd-mind BS but it does still happen.