Very much matches my experience with the last ~2.5 years of Rust. One of the really eye-opening ones for me was building a UI library on win32 and watching it just work on Linux, OSX, Android and WASM(with some Canvas work). Obviously each platform took some work to build out their respective rendering primitives but the core engine(including embedding Lua via gcc crate) just worked. As someone who's done x-platform…
And of course Smalltalk images can be saved on one platform and restarted on another, but that's with a VM.