Sadly, IMHO, old fax technology which was initially based on 14.4 kb/s or slower modems
using phone line has never made the jump to modern higher speed internet connections. And until that is corrected, we will never reach fax nirvana, and instead remain mired in primitive.
But the best way to fax, is well duh, with a fax machine. But I should qualify that remark two ways.
1. It only applies to fax machines with their own built in modem, not the case in all fax machines. And to use a fax machine, you have to have a conventional voice telephone line at that location.
2. We have to make one huge distinction with fax machines, because there are two kinds of faxes, outgoing and incoming. With incoming faxes, you must be connected to a phone line and your fax machine must have some means of processing and then printing the fax. With outgoing faxes you can buy all kinds of used ink jet printer AIO with their owns modems, for dirt cheap at your good will store. No damn need to feed them expensive rip off rate ink jet cartridges, they outgoing fax fine without them. But with incoming faxes, you have to have a means of printing them, and then with an ink jet, you fall into the trap of rip off rate ink jet cartridges.
Its why I have two backup outgoing fax machines, and one laser based AIO for incoming or outgoing faxes I got used for $60.00 two years ago.. Because I live in a rural area, I estimate I save $10.00 I would other wise have to spend on gas on a trip to town every time I fax. Most of the time my faxes are outgoing, and since I do not have a dedicated fax line, I need advance notification for incoming faxes.
With the laser AIO, 99% of the time it remains powered off and disconnected from a phone line to prevent lightning damage, but in less than a minute I can power on and connect to a phone line, to fax, and it also doubles as a compute printer.
If I need ink jet technology, I use my networked wife's non chipped Canon ink-jet I refill.