Both are leveraging declarative syntax to describe how the interface should appear as opposed to manually constructing interface elements and wiring them together. Both are state driven.

And both work across multiple platforms to "do the right thing" on each. As an example, a Toggle would look and behave differently on iOS, macOS, and tvOS, but act the same from a behavioral perspective.

Google also has Flutter/Dart, which runs off some of the same principles. Compose is just a different version of the same for Android/Kotlin. Also, I believe Compose only reached Alpha status last week.

Bottom line is that "traditonal" application construction techniques are difficult, time-consuming, and prone to error... and everyone is trying to get around that in their next-generation languages.