[Polylactic_acid]

HFP mode is not worth using for anything unless you are roleplaying a person from the 90s taking a phone call in the car.

The sound quality is truly awful in HFP mode, I can hardly understand what people are saying when in that mode and you sound horrible to everyone on the other side as well.

[lxgr]

HFP supports multiple codecs, and if your headset and source support the more modern ones (e.g. mSBC), this is no longer true.

[kn100]

Important to note that afaik no Linux distro supports anything other than potato quality HFP at the moment - at least that's been my experience.