Learn the difference between IFR and CFR.
2.83% is the CFR.
0.1% is the IFR.
As an example - my wife and I had COVID-19. My three children most likely had it but we did not torture them with the brain poking swab. They are not recorded in the official stats and as such are part of the IFR caseloads that do not get recorded in the denominator for COVID-19 official CFR.
I’m very familiar with the difference between IFR and CFR. That said, no-one knows the real IFR, because (as you stated), IFR includes people who have not been tested but are assumed/thought/guessed to be sick - which is all but meaningless as those assumptions may be close to accurate or on the other hand, woefully inaccurate.
What matters to me is the # dead in the universe of confirmed cases. There’s no denying (based simply on the raw data) that the *C*FR is > 2.8%.
That said, and as I mentioned earlier, it’s not just death that is an issue - 30+% of asymptomatic and symptomatic cases are reported to be having major lingering health issues, like the 30 year old “perfectly healthy” rock climber I mentioned who now can’t even walk half a block because her heart rate randomly jumps to ~180 just sitting. And many of them are quite serious / debilitating - possibly for the rest of the unfortunate person who contracted COVID’s lifetime. It seems that aspect of things gets “downplayed” and/or ignored way too much.