What kind of apps do well these days if not niche ones? I am more of a web dev so curious if theres something inherent in app economics that makes it so.
App economics are just bad. Most of your competition will be free to download but then trick / bully people into a subscription. And maybe a few lootboxes?
CLV for a free game can easily be $5+ and that means when you market your niche app you compete for ad slots against people who are happy to pay $1-2 per install. But for a $1 app you can at most pay $0.7 per install after the store tax and then you're not making any revenue to pay for support, development, and the devices you need to buy for testing.
Consumer SaaS is booming on mobile, there's a lot of money to be made but it requires bigger teams and investments now than it did 5-10 years ago. OP is right in that it's harder to have a lifestyle business selling small apps.
CLV for a free game can easily be $5+ and that means when you market your niche app you compete for ad slots against people who are happy to pay $1-2 per install. But for a $1 app you can at most pay $0.7 per install after the store tax and then you're not making any revenue to pay for support, development, and the devices you need to buy for testing.