Although you have received two posts on the benefits and technical aspects of HF, the abbreviated answer is we (almost) all use VHF all the time. Most aircraft don't even have HF radios fitted, and most pilots from basic PPL through to commercial pilots will go their entire careers without ever using HF.
I have to disagree with the above.
we (almost) all use VHF all the time.
If you are within range ,( ie line of sight) then you will use VHF, but a lot of flying involves crossing oceans and deserts. A lot of aircraft spend most of their flight out of range and unable to use VHF.
Most aircraft don't even have HF radios fitted
Of the 30 or 40 airliners I have flown every single one had two HF radios. About half of the G.A. aircraft I flew had HF radios and often on charters HF was all we had to communicate.
and most pilots from basic PPL through to commercial pilots will go their entire careers without ever using HF.
I can't refute that from personal experience but I'd be amazed if it was true. What do you base that on CJ?