There have been 66 cases in the United States in 2025. It just hasn't worked out how to spread human-to-human yet.
You are completely correct. We haven't had a plague recently enough that anyone has any idea what it's like.
For Ebola, H1N1, SARS, we treated them like an urgent global emergency, because that's what it is. I think Covid gave people a false sense of security, because it had a 3% case fatality rate even before the vaccine.
Last I heard, the H5N1 case fatality rate was about 30%. It's hard to say what a new strain's fatality rate would be. But that's what it was, the last time I checked.
And there are entire dairy farms where every cow has it, and they're just going in, milking the cows, getting snot on them, and going home.