During the pandemic of 2020 Zoom won the video conferencing wars. The word "Zoom" itself became synonymous with video conferencing, like Tupperware or Kleenex. Skype had at least a decade head start on Zoom but it was treated like the program you only use if there are no other options. I have to use Skype once or twice a year and it's always a bad time.
Skype's biggest problem is how it believes it should always be running. It can't accept that someone just might not want to run Skype 24x7. It's a very needy, insecure application that requires constant attention. On Ubuntu, and I assume other Linux distributions, it registers itself as a startup application at every opportunity. This is a quick article on one way I found to permanently stop this behavior.
Please, before you email me to say "just thought you should know that Skype has a setting to disable autostart" let me assure you I tried that setting. Skype randomly changes it back all the time, all.. the.. time. It's really horrible in this way. The option that finally worked for me goes like this...
First off, let's go to the autostart directory and see what's there. I deleted the Skype autostart file to show how this looks at the beginning. You may have different files here of course.
I'm not a huge fan of working in terminals. When I first used Amiga Workbench I vowed to never go to back to command line. If there's anything that can only be done via command line I usually write a small utility to cover it. You can get to this directory via a terminal if you prefer.
When Skype is launched it creates an autostart file.
Despite my aversion to working in the terminal.. sudo gedit ~/.config/autostart/skypeforlinux.desktop is the fastest way to open this autostart file. Skype predictably set X-GNOME-Autostart-enabled to true.
Setting that to false is easy enough.
The problem is Skype could still go back and set it to true. Spoiler alert: it will. So I took the additional step of making it not writable.
Now when Skype launches it can't update the autostart file or delete it to create a new one.
You're still stuck with this configuration file but with Skype being unable to change it the problem is at least solved... until Skype starts creating a file with a different name. When that happens I'll make the whole directory read-only which I'd like to avoid.