Not sure how the WGA operates but it's pretty common to have reserve funds for strikes as well as doing fundraisers and whatnot

Most/all unions keep a “war chest” to pay members during strikes, but the pay rates are usually far below members’ normal earnings.

I was in a UFCW strike when I was young, and the union paid us all minimum wage. For most of us, this was less than half what we’d been earning.

I literally have no idea, but I assume that the strike cannot go on forever. Though, since I made my previous comment I've learned that the striking members are still able to work, so long as it isn't WGA specific stuff (which seems fairly obvious, and I feel dumb for not realizing it). So, while it's lesser paying stuff, those who really need it can still get work to hold them over.

As a Teamster, if I strike I get 80% of my pay (well above minimum wage) and I get their health care. Starting day one of the strike. Used to have to be on strike for two weeks, but it changed.