I actually evaluated whether it was plausible to use a ChromeOS derivative as a workstation OS while I was at Google. At the time the answer was "no" for a bunch of reasons, including the following:
1) Crostini didn't integrate with the ChromeOS accessibility infrastructure, so it wasn't practical for users who required assistive technologies which meant gLinux would have to be supported anyway
2) While there is some degree of support for graphics acceleration for Crostini instances, there's no real way to provide direct access to the hardware. A bunch of people needed to do work that required more direct GPU access (either very resource intensive rendering, or GPU-offloaded ML models and the like), which meant gLinux would have to be supported anyway
3) We were in the process of moving to using hardware-backed machine identity for Beyondcorp, and Crostini had no way of providing that and tying that identity to the host identity (you don't want a situation where a guest VM appears to be trustworthy when it's running on an unpatched host)
4) This was also before the acquisition of Neverware, which meant at the time that a team would need to be built to maintain a build of ChromeOS for generic workstation hardware
This was a few years back, and I left getting on for 18 months ago, so it wouldn't surprise me if this is reappraised at some point.
Isn't Crostini just a Linux VM inside ChromeOS? So you'd still be running some other Linux distro (I'm guessing gLinux itself) and not actually using ChromeOS for development?
1) Crostini didn't integrate with the ChromeOS accessibility infrastructure, so it wasn't practical for users who required assistive technologies which meant gLinux would have to be supported anyway
2) While there is some degree of support for graphics acceleration for Crostini instances, there's no real way to provide direct access to the hardware. A bunch of people needed to do work that required more direct GPU access (either very resource intensive rendering, or GPU-offloaded ML models and the like), which meant gLinux would have to be supported anyway
3) We were in the process of moving to using hardware-backed machine identity for Beyondcorp, and Crostini had no way of providing that and tying that identity to the host identity (you don't want a situation where a guest VM appears to be trustworthy when it's running on an unpatched host)
4) This was also before the acquisition of Neverware, which meant at the time that a team would need to be built to maintain a build of ChromeOS for generic workstation hardware
This was a few years back, and I left getting on for 18 months ago, so it wouldn't surprise me if this is reappraised at some point.