I've been with Heroku for 7 years and this is the first time in recent memory that I've seen Heroku completely go down. Nothing at all works.
As an aside, I spoke with our AE in early January on where they are going in dealing with AWS unreliability. One would think they would have a good answer. They don't.
I recall at least one of them I could not deploy new versions of my app though, which is pretty bad. I don't believe I had any downtime at all due to heroku platform outages in 2021. i believe you if you say you did though!
This particular outage definitely seems to be of a rare level of severity.
Didn't bring my deployed app down though! No user-facing outage for me.
This time my app was down for about 35 minutes.
It's much better than it was 5+ years ago. Back then they had almost weekly downtime.