It's both. Seattle is one of the most introverted cities in the US (socially, it's disproportionately shaped by the tech population). Seattle Freeze is a real thing. COVID also did a number on people worldwide.
Also, gloomy weather 7-8 months of the year makes you not want to socialize.
Also, gloomy weather 7-8 months of the year makes you not want to socialize.