It’s very new to the standard library (latest version of GCC this year was the first version to support it). Additionally, I’ve found that println adds 30+ seconds to my compile time even for hello world so I’ll be avoiding it unless I need it
True, but Hylo is so new that it's not even an established language. Plus using this should serve to higlight the differences the author actually cares about between the languages.
What machine / compiler are you on where the difference between these are 30 seconds? GCC is also quite a bit faster based off a quick tests in godbolt.
That is 50% increase.