When I first went down the rabbit hole on this stuff in the early 2000s, an H5N1 pandemic was considered potentially devastating on a scale from merely horrible (50-100mm dead at the low end) to possibly apocalyptic, meaning 1-2B deaths and a partial collapse of civilization. So it's worth a closer look at the numbers
I should add - the actual CFR for H5N1 is probably much lower, studies indicate something closer to 14-33%. That's compared to a CFR of 2.5% for the 1918 flu.
The 1918 flu probably infected around 1/3 of the population and most estimates have it that about 60-75% of the global population has contracted COVID at least once.
Conservatively, if 25% of the global population contracted H5N1 with a CFR of 14% that would be 294MM deaths globally, and about 12mm deaths in the US.
66% infection rate and a CFR of 33% would be 1.76B deaths globally, with 72MM American lives lost and a reordering of society, at the very least.
Happy monday!