About 25 years ago Julian Simon asks the same question. It is useful to think of whether this is better or worse today (I paraphrase):
Think about all of the solicitors knocking on your door, calling your phone, sending you mail, sending you e-mail or otherwise stopping you. What percentage of those solicitations is to collect funds for the organization to actually DO something that you care about? What percentage of those solicitations is to collect funds so that the organization can lobby government to do something (or not do something)? And how much effort in each of those solicitations is merely to secure funds so that more solicitation can take place?
My last solicitation was from the National Parks Conservation Association. Learn for yourself how they roll (I still contribute anyway).