This is what I mean when I say that it's usually not helpful to try to make claims about the world based on, "I'm really mad about the EMH." You end up making silly claims.
Geometric Brownian motion can't take negative values either, so I don't know what you think this proves. While it's true that stock prices don't literally follow geometric Brownian motions (+drift), you can't tell the difference from stock graphs. (You can tell the difference with statistical tests if you know what to look for, e.g. volatility clustering, but humans can't tell by eye, and naive classification ML models will not perform well.)
I will note that "stocks are priced via geometric browning motion" would satisfy the EMH. And that the underlying growth trend of GBM, in a real world, is, like, "the stock market actually values real things about the company that you can find out, but which other people have already found out."