The largest are probably mobile betting and allowing for instant credit card deposits.
There is also the fantasy of being able to win money but the reality that if you actually win money in a consistent fashion, you will be either kicked-off or your action will be severely crippled.
I'd like to think the emerging prediction markets, like Polymarket, are much fairer systems, especially for winning players, and would be much better than sports books like DraftKings, FanDuel, etc.
This does not apply to all bookmakers. Also, betting exchanges exist where the players bet against each other therefore there is no incentive for the operator to ban winning players.