I think this has been posted before, actually. The underlying concept, I get. But I'm not sure how it'll ever become a 'product'.

In addition to all that, I still fail to see how a blockchain would solve any of these fundamental issues.

Google Drive always fails to sync correctly on my Macbook as well, unlike Dropbox.

Is that the old client? Yes, it was never great for me either.

I had an alert to switch to "Google Drive File Stream" (and uninstall the old Google Drive client) that is some kind of virtual filesystem. I went ahead and did it but haven't used it much yet.

I found out about File Stream by accident, they haven't really pushed it.

It's only for g-suite (i.e. corporate) users, not personal accounts. It's up to your g-suite admin to push it. I've been using it for a few months and it's pretty good.