Two things are going on: (1) People are reporting problems because sites that rely on parts of Facebook's infrastructure (like identity authentication) aren't working normally (2) With Facebook's own very large DNS resolvers offline, other resolvers are getting massive traffic spikes (Cloudflare noted a 30x jump) as clients keep looking for FB/Insta/WA & failing. Smaller ones are getting jammed up by it. https://blog.cloudflare.com/october-2021-facebook-outage/

None of these are really "Internet outages," and they're side-effects of FB being abruptly offline, not a sign of systems independently going down simultaneously.