I think it's likely only possible if you've got a lot of games you've made, to make a living off just games on itch, you'd likely need between 1,000 and 10,000 games on itch to make a steady living, the odds that people buy a game is already low from a single creator so you'll need a lot of games to not only increase the odds someone buys a game but also enough people to make a living weekly.
Unless you get lucky and one of your games blows up and gets tons of reach online, it's better to also post on other places like reddit and upload to steam.