"In psychology and psychotherapy, existential crises are inner conflicts characterized by the impression that life lacks meaning."

When you take away someone's everyday routine, for many, this takes away their meaning.

existential crises are not only about existence in physical form, but the ego existence as well.

You wold have read hundreds of articles about it during covid and not even remembered:

https://uthealtheasttexasdoctors.com/news/finding-meaning-an...

https://news.olemiss.edu/finding-meaning-and-resilience-six-...

https://www.frontiersin.org/articles/10.3389/fpsyg.2021.6417...).