I tested this on FF/Chrome/Safari on an M1 Max, couldn't see any difference at all between FF and Chrome but on Safari it was incredibly slow (which actually let me drive the car, that thing turns fast). I also wasn't aware prior to clicking that it was even possible to create web apps like this.
That person (Bruno Simon) is fantastic at creating 3D experiences on the web. He has a course on three.js too that I hope to buy and go through hopefully within this year.
So far, I haven't found much of a difference in performance of websites but it's still early times for me.