The flip side is that we’d have a very hard time eradicating it, and if humans can’t acquire permanent immunity it will be around basically forever, like most other cold viruses.
I mean regardless of the actual CFR and R0 value, we can take a look at Wuhan, Spain, Italy and now increasingly likely NY to see the impact. I'm not an expert but I don't think a bad seasonal flu overwhelms the local hospitals. And this is with extraordinary measures being taken to boost hospital capacity already.
Happens all the time, most recently during the 2017-2018 season in parts of the US: https://time.com/5107984/hospitals-handling-burden-flu-patie...
Also keep in mind that COVID-19 would be quite a bit more contagious than the flu (so it would spread more rapidly) if this theory is correct.