NOT real simple
The Covid 19 testing is not as easy as testing your backyard pool water. Pool water test kits have been available probably 60 or more years and the chemicals and chemistry is relatively simple. If we needed MILLIONS of these kits, production would probably meet demand.
A CDC Covid 19 test kit includes the following: Reverse Transcriptase, Polymerase, Flourescing Reporter Dye to name a few. You probably can’t get these ingredients at a Big Box or small Dollar store. Tests produced by Biotech companies probably use similar ingredients. These substances must react in a precise sequence.
The virus has been studied for only maybe 16 weeks or so. The number of tests now available is quite remarkable, when the complexity of the test method is considered. Folks seem to think that test results can be quickly available, as happens when someone uses ABBIE’S LAB FOR DUMMIES manual on NCIS. Not the real world.
Note: While not a Virologist, I have spent many years peering into Petri dishes, and other Microbiology testing.