I'm running macOS Catalina 10.15.7 and today I have a problem with starting up programs.
If I try to open any application from the Dock, it'll bounce forever, and in some cases freeze the screen entirely. On the other hand, if I turn my Wi-Fi off, everything opens instantly. So the only way I was able to type this message was to turn my Wi-Fi off, open Google Chrome, and turn the Wi-Fi back on. This is completely reproducible, I have basically a clean install of the OS, and doing the typical things like clearing PRAM didn't change anything.
The issue is very closely tied to having Internet. For example, if I have Wifi on but the internet is not working, then everything opens fine too.
I strongly suspect that macOS is doing something dumb, like waiting for a response from a slow server before allowing an application to open, possibly as part of its mandatory notarization. Mathematica is infamous for doing something very similar, but there's an option you can select to keep it from trying. Is there something similar for macOS?
This is indeed a widespread issue, currently climbing up on HN.
/etc/hosts
by adding the line127.0.0.1 ocsp.apple.com
. That will stop the revocation checks each time you try to launch an app.