I've heard that messages not getting through federation in some cases is just a thing that can happen. How that's compatible with calling matrix as having good federation, I don't know.
I’m not aware of any scenarios, including this one, where messages don’t federate (unless the destination server has been unavailable and marked down, obviously).
No, you are making things up. That cannot happen unless the homeservers are not configured properly. If you don't have anything to back that story up, I suggest you slow down on making matrix look bad
Unfortunately I cannot find where I had read that, might've just misinterpreted discussion about delays as about dropping messages / interpreting messages as answers to questions I didn't actually post... Sorry for the unnecessary negativity!
in dzaima’s defence they did hit an instance here where messages were effectively dropped - but only because the matrix.org db was so corrupted it incorrectly quarantined them (and even then, they can be flushed through). corruot db is effectively an extreme form of misconfiguration, i guess.