The article is in many ways another example of how what is a scientific question is viewed through a lens of partisan political bias. Taking its points
1. Deaths lag cases — and that might explain almost everything.
This is foolish. Cases are almost entirely driven by the question of how many tests are taken and who is tested. When someone tests positive for the disease that is almost certainly not on the day they got the disease. Hence unless you are very careful about the populations being tested it is really difficult to find out what is going on.
The mistake they make in the article is to assume that the day on which we find out someone is infected is the date they are infected.
The best and most timely measure of trends is hospital admissions. The UK government appear to have stopped publishing these as the last date published is 1st July and has remained as such for at least a few days.
2. Expanded testing is finding more cases, milder cases, and earlier cases.
This is a bit more rational, but contradicts their point 1.
3. The typical COVID-19 patient is getting younger.
If you are finding people who are asymptomatic you will find more younger people. Previously a lot of people had the infection, but no-one knew.
4. Hospitalized patients are dying less frequently, even without a home-run treatment.
5. Summer might be helping — but probably only a little bit.
Because of summer people will get a letter initial viral load and hence are less likely to suffer severely/die. This will change in the winter.