No, this is completely removed from what you're speculating.
I'm not experiencing beach-balling or other freezes all over the Internet, rather I"m experiencing specific, reproducible freezes in only three situations, all of which I'll erroneously call "interactive."
Here on the FTM posting form I lose the ability to click within the box and on "Submit" and "Preview Post."
At New York City, NY 10-Day Weather Forecast
the time of day slider and clickable items stop working.
At COVID-19: Daily Voice's Interactive Map Of NYC Metro Area Cases
I lose the ability to manipulate the map and click within it.
And as I said both here and earlier, this is 100% reproducible, which automatically eliminates random ISP and server overloads from possible culpability. And the Safari issue, which is the first one I noticed, predates the lockdowns anyhow.
I'm fine with Safari; it works exactly as I like, as opposed to Firefox which makes me jump through hoops to accomplish even simple stuff that I can do easily with Safari. And Firefox's prefs give me nightmares.