the contents of the site: let's think about the changes that occurred with Panda which opposed the so-called thin contents, contents which were not very consistent and perceived as having little value
site navigation: some suspect that the recent Google Fred may have had something to do with ease of use, for example suffering from invasive pop-ups that are unpleasant for mobile visitors
In addition to these factors, we must take into account all those external phenomena that can affect positioning: a government decision on our business that makes it inconvenient, a competing service denmark whatsapp number database that suddenly becomes more relevant for our audience... There are many on-page and off-page conditions that affect positioning that we must keep under control, to have a clearer picture of the situation.
Google does not always inform webmasters about these updates, many times it is the SEOs themselves who exchange information among themselves based on the jolts found on the SERPs.
it can happen that an algorithm update acts on multiple factors at the same time : it can happen that those punished or rewarded are, for example, commercial sites in the technology sector only, based on the quality of the links and ease of use.
This makes it very difficult to identify a common pattern underlying drops and improvements in positioning , and requires in-depth studies and comparisons across hundreds and thousands of sites to reach (and not always) generally accepted conclusions.