Comment by Ayraa

Search Engine Roundtable conducted a survey after the medic update, here are the categories of websites that were affected: https://s3.amazonaws.com/images.seroundtable.com/google-medi... (Health accounted for the biggest percentage but there were many other verticals that were impacted as well.)

There has also been several core algorithm updates since then that have caused ranking drops and volatility across the board.