I certainly agree that the action of CTB is very frightening and the most dangerous thing we as mortals can do- so physically- yes- it's 'brave' to do it and I ABSOLUTELY hate it when it is labelled 'cowardice.'
It also involves overcoming a massive amount of fear and worry to carry out- fear of failure and the possible repercussions of that, fear of pain, worry of the effect it will have on those left behind, fear of a possible afterlife/ nothing (depending on what you believe in and how you feel about it).
As a concept though- I expect to the majority of us- an indeterminate amount more of this 'living' shit (possibly decades) likely sounds a lot more scary than an early exit. Especially IF you're not afraid of an afterlife/ a lack of afterlife.
Facing an afterlife you fear could be the bravest thing you could ever do- depending on how 'bad' you think it has the potential to be. It's the greatest unknown.
However, this is a very personal take on it but to my mind I suppose- whereas 'courage' is about overcoming fear of danger to do something you find scary, 'bravery' (to me anyway) contains a moral aspect. People we describe as 'brave' have usually encountered danger in order to protect or save OTHERS. We usually commit CTB to 'save' ourselves from our own suffering.
From a personal perspective, my Grandma was in pain everyday. I don't actually know whether she considered CTB but she certainly wanted to die. I believe she fought on for as long as she did mainly to be there for her family. I do actually see that as 'brave' act because it is selfless. I expect this will attract a lot of hate but while I think it is perfectly justified, I feel morally, suicide is USUALLY a selfish act. (Not saying it's 'wrong'- just saying it's usually motivated by our own 'interests'.)
So, on the one hand I would say it was brave to overcome social conventions and the all the fear surrounding CTB to attempt it. On the other, I think people who hang on to spare others of the grief it would cause are also brave.