Apple servers had a documented outage to the software updates.
This is why failures happened globally on November 12 during the launch day of Big Sur installations.
https://support.apple.com/en-us/HT201475 How to upgrade to macOS Big Sur
If you are having issues on or after Friday, November 13 and there isn’t ...
The trash 'pending updates / stuck items' answer didn't work for me. Nor is it convenient for everyone to just upgrade to Catalina.
What did work for me, was to connect to the Internet via a different network. I temporarily switched from our broadband (via our WiFi router) to 4G (via my iPhone's personal hotspot), and voila, app updates started working again....
Big Sur has just been released today. There's thousands of people downloading numerous GBs each all at the same time. Downloads are going to be slow and temperamental until the release settles down a little more.
Your network isn't the bottleneck here; whichever server you're downloading from has limited bandwidth to serve the hundreds of users that may be ...
I had the same problem. Let me first clarify what the issue is,
as the first respondent apparently had trouble understanding it.
Like the OP, I have a few Terminal profiles with black or dark
gray text on pastel backgrounds. For some reason, when macOS goes
into dark mode, there is some internal logic that'll invert this
#000000 (or close to it) text ...