What is the point?

Is the continued existence of a group/endeavour/whatever alone, reason enough to participate in said group or activity?

I don't think so. Some people seem to, but I think existence is a means, not a goal.

Do you not need reason to do a thing?

Again, I don't think so. It is human nature to want an objective meaning to their existance. But that is not a rational desire, it is instinctive and emotional.

Or do you just mindlessly do as you are told.

I've been accused of many things, but that has never been one.

I believe life has whatever meaning you give it. We were not born with a fate or destiny, but we do have the option of choosing one.
Life only has the meaning that we actively give it.
If someone does not choose a purpose, then they have none.

Surviving for survival's sake, or 'looking out for number one', is hedonism and meaningless.

True enough, there are always expectations placed on us by society. We still choose if we want to meet them. Even the basics needs that keep us alive are optional. Our eventual deaths are the only thing we don't get to opt out of, besides maybe the laws of physics.

Our choices might not always be good, and quite often there will only be one option worth considering. The part I draw emotional energy from is the fact that I do everything deliberately. Every time I eat a meal, or draw a breath, or take a shit, I'm doing that on my terms. I could just as easily not do those things, and never have to worry about doing anything again.