I will let others more qualified opine, but for me it was quite easy to use. I think Android has Kotlin, and imo Swift & Kotlin are not too different, which makes it easier for someone trying to build across two different platforms.

I like Swift’s use of generics and protocols (can’t remember if I am using the right terms), but I really didn’t like some of the more recent changes that obscured parts of the language behind unnecessarily obtuse DSLs.

That said, I think everybody enjoys what they use most, so I don’t see Swift leaving the Apple ecosystem in the near future.

These days I have been abducted by aliens, extra terrestrial beings, and program exclusively in Common Lisp, with its secret alien technology. Now THAT is a language I recommend, its simply amazing to me :)