For about five years, a studio could build a game in three weeks, buy installs at twenty cents, earn thirty cents in ad revenue from each one, and repeat. That is the whole of it. The games were a delivery mechanism for an arithmetic difference.
What actually broke
Install prices rose. Every studio ran the same playbook on the same ad networks, bidding against each other for the same cheap impressions. Competing for a fixed supply does one thing to price.
Ad revenue per user fell. App Tracking Transparency removed the targeting signal that made each impression valuable. The same ad shown to an untargeted user is worth less, and no amount of creative fixes that.
Twenty cents in and thirty cents out is a business. Thirty-five cents in and twenty-five cents out is a hobby you are funding.
What studios moved to
Hybrid-casual. Keep the one-thumb hyper-casual hook, then add progression, an economy, and in-app purchases underneath. Retention stops being a seven-day problem and becomes a ninety-day one, and ad revenue stops being the only line.
Longer-lived titles. A game that earns for three years justifies the production cost that a three-week build never could. More art, more systems, more live-ops — and an actual reason to open it again tomorrow.
Channels that are not the App Store. Instant-play web platforms do not charge for installs, because there is no install. That removes the acquisition cost from the equation entirely, which is a different answer to the same problem.
What this means if you have a back catalogue
Titles that no longer pay for themselves on mobile are not worthless. They are finished, tested products with no acquisition cost attached once they sit somewhere a player can reach them without installing. Porting an existing casual title to the web is cheap compared to building anything new, and the economics on the other side are different in your favour.
This is what we do day to day — casual game development at Factorial Studio.