In Azure for example, I created a few bash scripts give me things like average daily CPU utilization over whatever time period I want for any/all VMs using their command line tool.
I can't seem to figure out how to do this in Google cloud except by manually using the console (automatically generated daily usage reports don't seem to give me any CPU info either), so far numerous searches have told me that using the monitoring function in the google cloud console is basically the only way I can do this, as the cli "gcloud" will only report quotas back which isn't really what I'm after here. I haven't bothered with the ops agent install yet, as my understanding is that this is just for adding additional metrics (to the console) and not functionality to the google cloud cli. Up to this point I've only ever managed Azure and some AWS, so maybe what I'm trying to do isn't even possible in Google cloud?
Monitoring (formerly Stackdriver) does seem to be neglected by the CLI (gcloud).
There is a gcloud monitoring "group" but even the gcloud alpha monitoring and gcloud beta monitoring commands are limited (and don't include e.g. metrics).
That said, gcloud implements Google's underlying (service) APIs and, for those (increasingly fewer) cases where the CLI does not yet implement an API and its methods, you can use APIs Explorer to find the underlying e.g. Monitoring service directly.
Metrics can be access through a query over the underlying time-series data, e.g. projects.timeseries.query. The interface provides a form that enables you to invoke service methods from the browser too.
You could then use e.g. curl to construct the queries you need for your bash scripts and other tools (e.g. jq) to post-process the data.
Alternatively, and if you want a more programmatic experience with good error-handling and control over the output formatting, you can use any of the language-specific SDKs (client libraries).
I'd be surprised if someone hasn't written a CLI tool to complement gcloud for monitoring as it's a reasonable need.
It may be worth submitting a feature request on Google's Issue Tracker. I'm unsure whether it would best be placed under Cloud CLI or Monitoring. Perhaps try Monitoring.