If the bit is painful, the rider is wrong. But frankly, some of what you have heard is wrong.
The jawbone doesn't cut thru flesh. If it did, lots of horses would have bloody mouths. They also would be terrified of bits, and a great many are not even a little afraid of bits.
"those who ride in double jointed bits, when you pull that bit the joint jabs the top of the jaw
You are the first person I've ever seen who claims a double jointed bit will poke the roof of the mouth. That claim is usually made about single jointed bits, and is largely incorrect. Studies done with X-rays so we can SEE what actually happens show the single jointed snaffle will sink more into the tongue that it goes up to the roof, so there is normally no contact. There could be exceptions of course, but the common claim that a single jointed snaffle pokes the roof of the mouth is largely wrong. A double jointed bit will put more pressure on the tongue, but many horses prefer them.
If you take my mare out on a trail with a bitless bridle, she may be fine. Or she may run off with you...and if she does, you won't stand a chance of stopping her. People didn't invent bits for the fun of putting metal in a horse's mouth. They simply work better than NOT doing it, for the large majority of horses and riders.
You spent 2 years trying to put your horse in "an outline", which is certainly worse than riding her in a bit. Maybe you should have tried some time like this - and notice the evil
curb bit, cruel, cruel!:
But somehow, I doubt I'll change your mind...
Mia at the end of another painful ride, the bit cutting into her flesh:
Previous thread: Bits are painful!
And BTW - YouTube videos may not be the most reliable source of information.