go run works by compiling the program to a temporary executable and then executing that.
can you guarantee that runs everywhere
It seems to depend on glibc versions, if that's what you are asking. You can force it to be more static by using a static musl python or via other tools. Of course, a binary for Linux only runs on Linux and the same for Windows and Mac. But yeah.
Also it should be noted that go binaries that use C library dependencies are not truly standalone, often depending on glibc in similar ways. Of course, same as pyinstaller, you can use musl to make it more static.

Owncast is the self hosted stream thing. It has some rudimentary federation capibilities, but nowhere near the ease discovery of twitch.
I know some streamers that have an owncast, expired_popsicle uses debian Linux and has one. (It's tech/linux streamers because of course).