There have been some very ill-informed statements about the US and FAA, for a start, Class G airspace in US is very rare, transponders are not a universal requirement for VFR.
Stating that Class G airspace in US is very rare, would be one of those 'very ill-informed statements'. Outside of towered airports it extends from the surface to either 700' or 1200' agl across the entire country. I spend my life in it. In mountainous areas the rules can become fairly complicated, suffice to say that you can be flying around at 14,499 msl...in Glass G airspace.
Without hijacking the thread, more info here for anyone interested in what's happening in the USA in 2020:
https://www.aopa.org/go-fly/aircraft...b-out-required