A very reliable COVID-fighting technology that's been available for a while is the rapid antigen test. It's cheap, accurate and gets near-instant results.
If you own a business, you could realistically re-open your office tomorrow* with few restrictions by testing your employees twice a week. The benefit is that you would be able to detect infections with great accuracy, speed, send the sick home upon a positive test and keep everybody else productive. It really is that easy.
Sadly, it's a technology that's been completely ignored, if not outright banned in favour of the much slower and comparatively unaffordable PCR test.
While it's true that the accuracy of rapid antigen tests is slightly lower than PCR, it has also fewer false-positive, as the polymerase chain reaction (PCR) technology has a tendency to amplify trace amounts of the virus and thus label people as "infected", often people that are either asymptomatic or naturally immune and therefore not a proven vector of transmission.
The affordability of the rapid antigen test, combined with its near-instant results more than makes up for its inaccuracy, as two tests conducted within 24hrs of one another give you roughly the same accuracy as a PCR test for a fraction of the price and a third of the time.
What that means is that if you had a regular workplace testing protocol, you could realistically and with very little risk bring people back to the office tomorrow* while keeping your employees COVID-free.
There are even organizations out there that have been created for the sole purpose of widely implementing rapid testing in order to allow a safe return to normal as quickly as possible.
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*Note that how and when you can re-open depends on your local rules and whether your overlords™ want you to or not. I'm not advocating for breaking the rules and if you do so, it's at your own risk.