Faucets are usually important in gambling sites which are new. Many people do not be willing to spend on new gambling sites and prefer to play and test new site with free money. Sites such as stake which are already trusted and many people play there , there is no need of faucets.
Don't think that faucets are helpful for new sites and not the old ones. Remember there are new users who register on the old sites too and if there is a faucet on the site, they can play it using faucet money.
Faucet abuse is another thing and it should be controlled in some other way, not by closing the faucet.
There was two type of different faucet abusers who are really not all the reason why faucet was gone. One of them was people who only played with faucet and never deposited which wasn't the reason why there was faucet, normally faucet is there so that you can check the website and then stop using it and deposit some money to gamble, but I can understand these people, you can constantly gamble with faucet, and even maybe make some money with it once in 40 years or something because its rare and its fine, these people are not really the main reason why faucet was gone.
The real reason why faucet is gone was the people who used bots and other technological improvements to constantly bet and constantly wager to make as much money as they can from it without even working, they used it like passive income.