Yeah this is mostly the "build twitter in a day" projects that conveniently ignore the reason these companies have 10,000+ developers is the 99.9% of the software that is not the frontend that actually makes the company things happen at the company. The much bigger customers of many of these companies being the advertisers and the artists/creators who have their own interfaces and analytics and billing and payment tooling. The business rules engines and feature flags with tens of thousands of rules that allow any of these companies to operate in subtly different ways for customers in different states, countries, and regions with different laws for accessibility, fair use, and using and storing data. The auth and security layers that often have multiple interfaces for employees, customer classes, partners supporting native-auth, oidc, totp, developer tokens, etc... Apps for a dozen or more different app ecosystems on hundreds of device types from the obvious web and phone-based ios/android to the less obvious carplay, watch, roku, firestick, etc...