Well, my family over generations has gotten smaller and smaller. This basically means my mom's side is set and she'd basically get more than she earned her entire life, just due to how Austria pays out monthly a fixed amount, and social service etc. Is already taken out, so grandfather is at about 30 years of a very good retirement income, without taking income during his life into account, very good investments.
All grandparents in Austria are/were fine and earned above the min pension payout based on work, my dad's side the children donated money regularly, that was more to pay for holidays/trips and extra stuff, none were ever in danger of losing home or having to go down in lifestyle, mostly because all family has been very frugal.
That frugality for e.g. My dad was way too extreme imho, and he's probably saved 60% of his lifetime income in pension for him and my mom, and he earned quite a bit and never upped his lifestyle past early 30s/second job. He should have spent more if I'm honest, you need to balance saving and life quality.
So that side, don't expect to ever have to support them, and if I have to I'll probably refuse as I can't see anything besides a complete economic crash where I have nothing, or they end up in drugs or something. I do still give them other ways of support, and will probably do things like booking flights so they can come visit once I've properly built up my savings again.
That said, I'll probably end up supporting my siblings, neither of them will ever end up in a higher paying job, and I'll convince at least one of them to follow me I hope, not sure about the other, but I'm very worried about the one as I know they're already a bit jealous of my current salary since they got furloughed and then half salary with covid, meanwhile I started at triple their salary and am now nearing 15x their cut salary after promotions, while they'll maybe get to my starting in 20/30 years since the industry is garbage. And Cape Town is not cheap.