I just tried it shortly some years ago. Back then it was basically only the browser and some web apps if I remember it correctly.
Some time ago, I succumbed to the hype ( 
) and bought a Chromebook with a 10th gen Intel 5 cpu. It is pretty powerful for what it does and the Linux in the container runs pretty well as if it were native. And then there is Play Store for Android apps.
Arch Linux on Chrome OS
My guess is when Google is done with its plans to separate the OS from the browser and the OS becomes a more independent platform, and also with the rise in the market share, more developers will be making apps that can be run on the OS. Someday one might be able to run Photoshop natively or play one’s favourite games with the same performance in Windows or why not play them in the Linux on Chrome OS.
I am not a fan of Google and I have been and still am in the process to getting away from my dependency on their services but I find it fascinating what they are doing both technologically and also how they aim to get that bigger piece of the market cake.