Here in New Zealand, facebook handles a lot of the smaller scale commerce (like craigslist or gumtree might in other places), also many organisations and businesses only have presences on facebook. It's unfortunate, but there certainly are people here who are impacted by facebook outages.

I've heard that ebay's culture has a sense of responsibility to the people who make a living on their platform. As an outsider to both, it does seem like they owe their existence to their users so that sense of responsibility is appropriate.

Agree. I don't think something like FB or even Amazon.com going down has huge impact. People just come back later and get what they need done.

OTOH, having a subscription based service in specific going down can be catastrophic because you lose so much customer trust (think Azure, Spotify, etc.). In that sense, I guess amazon.com can be bad too with things like prime video, etc.

Why is that, is it incidental or based on the features they offer?

WhatsApp is a Facebook product.