https://www.intensivregister.de/#/aktuelle-lage/kartenansich...
https://www.intensivregister.de/#/aktuelle-lage/kartenansich...
If you can read German here is a source for Berlin: https://www.tagesspiegel.de/berlin/zu-viele-corona-patienten...
TLDR is only 85% of the beds are full, but there aren't enough nurses, so the emergency room will be closed. Several other hospitals in Berlin already stopped admitting new ICU patients.
https://www.welt.de/regionales/bayern/article161869919/Klini...
https://www.researchgate.net/publication/333785335_Managemen...
And if it is really such a limiting factor, the statistics should be adjusted accordingly.
I think it is just a wildcard argument without any specific numbers. You can imagine whatever you like. How many nurses are available? How many are sick, specifically?
Also, sick nurses tend to be well again after two weeks (if they have Covid).
Optimal rate depends on the country, but about 75% is typical.