That said, they have less of a safety net than the others, with no cable deals to fall back on (which are steadily eroding from underneath the others anyway). However, they seem to be very good at knowing how to run their business, so I wouldn't count them out unless some outside forces take effect.
Their name has been synonymous with streaming for a decade, which will keep them entrenched at least a while longer than they would otherwise deserve.
I think if they had a serious stumble, Amazon would just buy them anyway.