Lead. You have the classic Bloggs belief that only if it's mandated do pilots act responsibly.
In the USA there is no mandatory radio requirement for VFR in E or G airspace ..nor any mandatory CTAF calls.
That doesn't mean pilots don't have radio and don't give the necessary calls.
In Australia I reckon most pilots give a taxiing and inbound call on 126.7 where they think it is prudent to do so.