Because it's the only major platform with a robust API. In 2022 I don't think any other major service has a public API that lets you perform as many actions as

Because it's the only major platform with a robust API. In 2022 I don't think any other major service has a public API that lets you perform as many actions as the official website or app. > Adjacently, why don't they allow non-first-party apps? Because if they are the only option, then people will only use their app, which means they can do whatever they want with it and people will still use it. Additionally, they no longer have to maintain or work on a public API.