I think a lot of charities have outsourced their collection efforts. If so they will have a fixed term contract, and the collection companies, I am guessing, would also have asked for exclusive rights to collect on behalf a charity, and some charities would have given it to them. It is the over assertive collection companies that are the problem, and RNLI has no control over them, until contract renewal.
I can understand charities doing this outsourcing. The treasury side of things (counting and banking) is a huge job, with a big overhead. All electric banking is more secure, and minimal chance of 'irregularities'. I am living in China now, and even the beggars have a card with a QR code on it, because most people no longer carry cash.