The Core

And last week, as a wave of stay-at-home orders rolled out across the United States, the average time it took to download videos, emails and documents increased as broadband speeds declined 4.9 percent from the previous week, according to Ookla, a broadband speed testing service. Median download speeds dropped 38 percent in San Jose, Calif., and 24 percent in New York, according to Broadband Now, a consumer broadband research site.
https://dnyuz.com/2020/03/26/surging-traffic-is-slowing-down-our-internet/

Cloudflare sent out an email yesterday saying they are seeing a 10-30% surge across the board

I assume it's from all the people at home industriously writing lots of emails.