At one time, when I started, sports books comped real well. A dollar bet on sports got you as much as a dollar bet in the race books. The best at the time was Circus-Circus, believe it or not, where I think it was $125, and then later $200 bet, got you a dollar in comps. Pretty soon, the best you could get was roughly $400 bet got you a dollar in comps, at Westgate and another place or two. By the time I finished, and why I started playing some video poker in the first place, many places had squeezed off sports betting as something that should be comped. The Wynn wanted 20K in action to give you lunch that day.
And this doesn't even address that, initially, you could get discretionary comps. Sports book knew you, you'd just ask, no formal process needed for breakfast or lunch. Today, if you ask for a discretionary comp, they look at you as if you asked for a kidney.
However, now that sports betting has become multi-state for some of the big corps, there are some comp comebacks available for sports. I mentioned this in a comment to a Jean Scott blog. I'll keep that under my hat until next year, but some comp things got easier.