Take a look around right now, multiple states are at ICU capacity. You don’t need to overrun the hospital system but under sustained stress, you quickly degrade service. Not to mention all the burnout and people leaving the field on top of it all.
You can go back and look at 10+ years of UK NHS "hospitals desperately overwhelmed" annual articles. Just because you hadn't heard of it before doesn't mean it isn't normal.
In the US, they've relaxed many guidelines and allowed student nurses without gaining licensure yet to practice because of the need [1].
[1] https://www.healthaffairs.org/do/10.1377/hblog20200327.71403...