..... and we know that in the case of sports betting the house edge can vary wildly and you do not want to make a bet in anything that has a house edge otherwise your chances of beating the casino become minimal.
I don't see any house edge on casino, but that's just for me.
You are not being against a casino when you put your bet on sports, you are betting against the bettors, casinos just take a portion of your winning which is the juice, normally 5% to 10%, depending on the sportsbook, but for me, normally I do bet on odds high that +100 so I don't have to pay for the juice.
I suppose it depends on your perspective but if a casino takes a portion of your bets to me that is the house edge, it is true that you are not competing against the casino when you bet on sports but still they do not offer their services for free so we may call it a fee instead if that is what you want but the end result is the same, you do not earn as much money as you could have in the case such a fee or house edge was not in place.