Somewhere, someone is saying the marketing is fine since 100 has just 1 significant figure and therefore two nines -- no, one and a half nines -- can safely be written as 100.

If they are truthful it will now probably change to 99.997% uptime or similar. I expect that's still good compared to many DNS providers.

Some dns provider only have one name server which is naturally bad.

However it is a bit bad of CF that a single configuration error can bring all the slave servers down. It mean that they have no redundancy in term of BGP misstakes. Customers of CF that want to avoid this would benefit to add an additional slave server outside the hand of CF.

Zonemaster (dns sanity checking tool) actually complain about CF hosted domain names because of the lack of AS redundancy. The outage yesterday demonstrate nicely why that is an concern and why one should care. https://zonemaster.iis.se/?resultid=7d1fab165987e195

Same goes for route53 too unfortunately