I would add to this that certain combinations of modern SSDs (like nvme) can put disk performance equal to or in excess of RAM performance, too, so there are ot

I would add to this that certain combinations of modern SSDs (like nvme) can put disk performance equal to or in excess of RAM performance, too, so there are other considerations besides resilience, too. I've seen people do this for DB-intenstive things like large search server deployments and map rendering. Doesn't take many nvme mirrors to get past DDR4 speed.