The ideal would be for each player to bet on what he has the most affinity for and identifies with the most, i.e I really like football, so the tendency would be to bet on football
Yes, you're right, the more you understand the type of sport you choose to bet on, the more knowledge you have to use as consideration in betting, but that also doesn't rule out the chance of losing.
He said that basketball is more profitable than football because of this.
Whether it's true or not has to be done by comparison, we can't just bet on one type of sport and then say there's a greater chance of winning because we've never tried another sport.
I only occasionally bet on basketball and more often on football so my judgment is not valid unless I bet with the same frequency between football and football.
However, I don't watch basketball and I don't know the basic rules of this sport, despite it being fun.
You can learn the basic rules by reading articles on the internet without having to watch the match, but for me about sports learning while watching is more interesting compared to learning while reading.