How are you concluding things are winding down?
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.
Based on what. Your gut? Ok Trump.
Look at how fast it's continuing to the spread in the US even with all the drastic measures which have taken place in some areas. If you can't imagine what it would be like without these unprecedented closures then I'm not sure what else to say to you.