Not bad points.
However, in an entire country, barring major policy or testing shifts, “errors” will largely factor out of cases’ curve velocity and acceleration, leaving those as useful information. Large changes in CFR are also useful info. For example, if infectiousness / case numbers surge by 10x with a new variant, but fatalities only increase 2x, that’s very useful info.
Agreed.
But there are other variables. Maybe the biggest is vax duration. The vax loses its defense against infection before it loses defense against death. So a variant appearing nearly a year after vax can spike cases but hold deaths down.
The stats will then not describe variant performance.