...there are apparently a lot of people who test positive without symptoms.
Do you have any references for this? I'm sure some people test positive for SARS-CoV-2 virus exposure before showing any symptoms of the COVID-19 disease (especially with such a long and variable incubation period), whether they later develop symptoms and sickness progression or not, but I have not found any data with real numbers tracking this, how many really remain completely asymptomatic until their body learns to kill it off completely.
Also, while I keep seeing random claims that there are huge swaths of general population that have been exposed and fought it off without even knowing they had it, which would eventually lower the death rate once those asymptomatic cases are eventually discovered and recorded (from post-outbreak antibody screening, etc.) I cannot find any data supporting this claim. The only data I can point to thus far actually suggests otherwise.
For example, the 320,000 tested in Guangdong was a rather wide sampling of the general population and they did
not find a plethora of un-diagnosed cases among the general population once the initial wave was under control, suggesting that the number of true cases has
not been underestimated there.
The same thing has essentially been showing up with our testing here in Alberta. As of Friday we had tested 20360 people, anyone who has shown any possible symptoms or has been exposed to someone known to have the virus has been tested. To Friday, that was one test for every 215 residents. Only 195 cases were found, so less than 1% of those tested have actually been found to be infected.
This mirrors what was found in Guangdong, where it looks like no, it has probably not already spread as widely among the general population totally asymptomatically as some people are thinking. Now, of course, we haven't tested everyone but if we've tested a whole bunch of likely-to-be-infected people and found less than 1%, it doesn't seem to show there already being a huge undetected infected group that will eventually be found to push the death rate down by an order of magnitude.
Only time will tell. Stay healthy, my friends!