The amount of money you earn from a website depends on the amount of website traffic you have and if you're using Adsense it depends on the amount the Advertiser is paying for the ad click.
Some Ads pay higher than some other ads.
It took me 5 years for my website to earn a decent amount of money from Adsense. But I still haven't reached enough to fully live off of.
Some people can earn more money on their website with less time and traffic and others it takes a long time.
Don't expect to put up a website and quit your job within a year it's not realistic.
Earning a living from a website can be done but it can take years to achieve that goal and some don't even make it.