I’ve experimented with using gcsfuse and its AWS equivalent, s3fs-fuse in production. At best, they are suited to niche applications; at worst, they are merely nice toys. The issue is that every file system operation is fundamentally an HTTP request, so the latency is several orders of magnitude higher than the equivalent disk operation.

For certain applications that consistently read limited subsets of the filesystem, this can be mitigated somewhat by the disk cache, but for applications that would thrash the cache, cloud buckets are simply not a good storage backend if you desire disk-like access.

What I would really like to see is a two-tier cache system: most recently accessed files are cached to RAM, with less recently accessed files spilling over to a disk-backed cache. That would open up a world of additional applications whose useful cache size exceeds practical RAM amounts.