A simple 'ls' listing of a directory can take 30 seconds of more to complete.
Most programs are giving up before the directory list is available. Such as an FTP server listing a folder in the bucket.

I am currently using these mount options
--stat-cache-ttl 5m
--type-cache-ttl 5m
They seem to have zero effect.

ie An 'ls' of the same directory in quick succession results in the same 30 second wait time

All sub directories seem equally slow regardless of content.
Listing of empty folders is slightly quicker

gcsfuse installed from google yum repo