> We all have seen the images of hospitals overwhelmed with COVID-19 patients, not having enough breathers, etc. For some reason this doesn't happen with the typical annual influenza
Are you sure about that? it's probably not the same extent as what has happened with covid-19, but some hospitals do get overwhelmed during flu season.
A quick google search pre-2019 returns a lot of results, for instance:
https://time.com/5107984/hospitals-handling-burden-flu-patie...