Lots of ChromeOS misinformation in this thread. Llaallaa7712 is correct in every thing they said - props to them for getting it to work!
ChromeOS itself is a linux based distribution with a Desktop Manager that features primarily a Browser experience. On higher end devices a linux VM capability called Crostini is the layer Llaallaa7712 mentioned that you can turn on to enable a linux environment that is capable of running terminal and GUI programs. This is a "first class citizen" of ChromeOS and not some kind of hack or workaround. So they were, in fact, running OBS on ChromeOS.
Games, productivity applications, and programming workloads (to name a few use cases) work just fine through this layer and it is highly configurable and extensible.
In the future we may see more "gaming" ChromeOS devices as a lot of investments are currently being made in this area and there is already a beta version you can try today of "Steam on ChromeOS" available on some higher end devices. I would not be surprised if this question gets asked again in the future.
Interestingly people often misattribute a lack of functionality to ChromeOS devices due to their original design. Although the full suite of capabilities is usually limited only to high end devices if you take the HP Elite Dragonfly Chromebook as an example as an "Enterprise device it can run:
* web pages in the native Chrome Browser
* android apps with first class support and google play services support out of the box
* linux cli and gui applications
* windows via parallels
This is quite the feature set and I am not aware of any other kind of device that can do all of these things out of the box and without any significant configuration.
Finally, ChromeOS has a screenshot and screen recording capability available out of the box and has for some time.