Yeah, I've had the same thoughts...
I see a lot of people online starting tarot businesses that they do full time, but at the same they are economically supported by their spouse. I could never do that, I need to have my independence and private finances to feel like a free person.
It would be wonderful to work full time with tarot and healing, but it really is hard for most of us. It takes years to build a stable client base, and the competition is usually quite tough.
But I must say, don't underestimate how much fun a "hobby business" can be! I've very much enjoyed selling readings through my Etsy shop. Some days it has been tough, when I've worked my 8 hours at my day job, come home hungry and tired, and had to finish two big readings... But so wonderful being able to help people, even if it's the only two people I read for during one week.