The point was that most of these things become less relevant when the surface area of the codebase gets smaller. Individual utilities are generally easier to understand, test and debug as separate units, logging is already baked into the system (syslog, anyone?), and why would you need analytics?
Homegrown solutions require varying levels of support. Something like Slack is predictable and that makes it attractive, from a business perspective.
Furthermore, debugging may be "easier" insofar as the units are discrete (though any good modular architecture will have the same advantage), but what do you do when you find a bug? If you're running a business, you can't be in a place where you're just submitting it upstream and telling your customers that every single bug is waiting for a vendor fix. So now you have to take ownership of maintaining and repairing each and every UNIX utility you use. In what world is that easier than having 500k lines of Go in a consistent company style?
Joel Spolsky's advice is pertinent [0]:
> If it’s a core business function — do it yourself, no matter what.
https://www.joelonsoftware.com/2001/10/14/in-defense-of-not-...
Screen sharing and video calls can be handled by other apps like Zoom, Google Meet etc.