As an example, "Save the Children" is one of the organizations that is part of the coalition trying to backdoor encryption. It brings in over a billion dollars a year. Here's its institutional donors list, in the attached image. Mostly government.
Here's another observation: privacy advocates like to say that "nothing is actually being done to help children" but you look and a lot of these organizations in fact do tons of work to materially help children all over the world. Tech liberals are going to have to come to terms with the fact that big, important child welfare organizations just plain want to take away your privacy, it's not all just a big front for data brokers or something, who don't care about kids at all.