Maybe they are different in other countries (and maybe you have fewer options in other countries) but in the USA they are very, very inefficient, have had a few scandals, and few people seem to know or care.

Just google the fiasco with what they did with the millions they got after 9/11 when people had impulse to donate but didn't bother to research alternatives. Local chapters kept funds meant for 9/11 and the national headquarters used some of the funds to buy nice furniture for themselves.

The reality is if you want your donation to go towards a specific cause, you are always best off finding a local charity that is smaller and highly optimized and already has "feet on the ground" in the area.

Randomly throwing money at causes to make oneself feel better is wasteful and defeating.