Right but it's also astonishing that was allowed before. If it's not needed for work why would it be installed? Why would any non-work software be allowed on corp laptops?
Because unlike most large workplaces that inhibit innovation and productivity and infantilize staff with an “anything not specifically permitted is prohibited” rule which also creates continuous work for a review and approval bureaucracy and guarantees that toolsets are outdated and improvements difficult to discover, Google apparently has an “everything not specifically prohibited is allowed” policy.
There's a third "use at your own risk" option between the two extremes. Sure, install your favorite terminal emulator, but if it steals your production credentials you may get fired...
Because then you don't impede people who might need a new widget installed because everyone and their mother in IT needs to try it and test it before you can use it.
Especially at Google scale, where the BeyondCorp system described in their papers could automatically see when an endpoint was doing something naughty, block the user from accessing corporate resources, and give the user information on how to fix it, instead of blocking them from installing anything (even if what they want is perfectly harmless).
Google allows personal software to be installed in a corp laptop, subject to restrictions and limitations like this. It's not encouraged, though, and if something happens because you installed a third party software then it's your responsibility.
Google has always had the company culture of not infantilizing their employees and broadly trusting them to do the right thing. This reflects in many many policies and general 'culture'. You can install software on the laptop as long as you have the right license for it, and there are centralized tools to check for potentially dangerous binaries and things like that.
With videoconferencing you aren't always in control of it, especially if you interface with other companies. I have webex, zoom, bluejeans, teams, and skype4business on my laptop because I am a consultant and have to use whatever my client is using.
There's also that zoom free tier creating a 'Shadow IT' situation. Slack used this to great effect and everybody on HN was very impressed. It should be no surprise that Zoom is finding its way onto random employee laptops, that is something tech firms are trying to do on purpose now.
Generally you can install anything, but the responsibility is on you though. It's not uncommon to see people with Steam, Spotify or other personal software too.
Because sometimes there are contractors, or consultants, or vendors, or partners you work with that for one reason or another can't use internal options.
It was banned as in it can no longer be installed on corp laptops.