Dart is also a Google conceived language but it’s not exactly what I’d call popular despite only hearing positive things about the language itself.
Unlike Swift or Kotlin that are heavily entwined with the main mobile platforms, nobody needs to use Golang for any particular reason. As far as I can tell its developer experience is pretty good so people have opted for it because it fits their needs.
This is a good example of why a big name doesn't guarantee adoption. Look at failed Microsoft development stacks too, and hell JavaFX had potential but I have seen zero effort from Oracle in terms of UI libraries. It's a shame, if Java could produce a serious UI solution I would of crawled back long ago. I can only hope Maui runs on Linux eventually.
Unlike Swift or Kotlin that are heavily entwined with the main mobile platforms, nobody needs to use Golang for any particular reason. As far as I can tell its developer experience is pretty good so people have opted for it because it fits their needs.