The virus exhibits seasonal effects. There is no denying it. It does not mean it is seasonal, in the sense that there are well-established seasons for a virus that has become endemic and has periodic resurgences. It was (and it still is to some decent degree) a new virus...

... that is affected by seasonal factors. It does not mean that human factors, meaning human choices, have no effect.

Here a graph of deaths in Sweden, Finland, and Norway between Sep 1 and Oct 31, and...

... here a graph that included the subsequent period.

Surely that can be explained by prior infections and deaths in Norway and Finland, as...

... it can be seen in this graph that now includes also the previous period.

Also, surely...

...Norway is experiencing some weird seasons

People...

... in Turkey are quite confused, and so are people...

.. in Iran, who start to wonder about the many seasons they have.

Furthermore, ...

... Poland and Germany look at each other puzzled, and we can...

... reinsert UK for good measure.

So, this is my take:

Seasonal factors play an obvious role, but negating the human role in modulating the virus is quite silly. There are extreme cases of modulation, like the countries that have gone for elimination or at least hard mitigation

The first tweet in this thread should have included this tweet, that appears as a comments in a thread by @fatemperor where he denies essentially any role of human interventions, even vaccines... https://twitter.com/Marco_Piani/status/1388404916037763073?s=20

... on the altar of "seasonality", his beloved creature that he mixed up pretty well with the notion of herd immunity achieved in Sweden last Summer...