Go is my favorite language of all time, but it is my favorite language because of its inherent simplicity for a modernish language...and all the setups required to try to use it as mobile app development platform that I've seen are the opposite of simplicity.
When it comes to mobile app development I'll stick to Kotlin Multiplatform with Compose Multiplatform. I love Kotlin less than I love Go, but its still pretty good and its much simpler to write 99% of the app in Kotlin and Compose and just have a very small amount of platform-specific stuff in expect/actual functions than it is to deal with layers and layers of shims pulling together various technologies that were not designed to work together.
Kotlin is great on the server too.
KMP is brilliant and arguably the best way to write a cross platform app that has Android as a target.
But what you can do with it on non-JVM platforms is a bit lacking. There are few libraries and the stdlib is rather minimal.
If you're just making some http calls and instantiating models it's pretty good though!
Shame it's part of the Grade hellscape though ;)