That is very simplistic. There are a lot of other recurring costs that charities have - even the ones you mentioned have to pay rent at least. A women’s shelter probably needs professional employees. Some charities have to operate planes and boats and those are very expensive. The most important thing is - recurring contributions help them plan long term and realistically gauge if they can take on more projects.
Also, calling a monthly donation a “subscription” is stupid. You didn’t sign a contract - you can just stop giving the money whenever you want.



The only weird thing I sometimes witnessed was that, when I waited tables, Americans paid in Euro or via credit card and then proceeded to leave me a tip in US Dollar. Surely this poor European must crave the strong currency of the US over his weird colorful banknotes.
Oh, and in northern European countries they stick out enormously on account of their loudness when just speaking amongst themselves.