I have various charities that I support. They mean a lot to me. I've looked into them carefully and am satisfied that the money I give is used in a way I am happy with. If I had any extra money, I would give to one of them.
I have no interest in giving to a charity that I know very little about and is less of a priority for me than the ones I support. I think it's good that we all prefer different causes and support those that mean something to each one of us. But just because it means a lot to you, doesn't mean that it's something I would prioritise.
Any gifts I do make to charity I give direct to the charity, not via someone else, who may, or may not, be using an organisation that helps itself ('for costs') to some of the gift on its way to the charity.
And I certainly don't wish to give money to people for doing some hobby or challenge. I think most, quite likely all, people do that because they want to and then add the charity to make themselves feel more virtuous. After all, if supporting the charity is their aim, why not just give the money direct? If you really want me to give to a charity that feels important to you, ask, explain why and I might make a donation to them direct.
See also the dreadful 'I couldn't be bothered/didn't feel like paying to send you a Christmas card this year. But because I want to feel like I'm nicer than that makes me appear, I shall make a donation to the charity of my choice, regardless of whether or not you would want to support it.' Send me a card or don't. Give to charity or don't. No need for an announcement.
TL:DR. Give to charity or not. Your choice. The performative bit is unneccesary.
Edit: to replace a line that disappeared.