I've been using Paperless for several years now very happily and can recommend it over my previous system, also Google Drive. During the transition I found it helpful to set up a cron which (A) made an export of Paperless and (B) uploaded that export to a Google Drive folder.
One feature which seems to be quite a nice improvement (speculating as I haven't upgraded yet) is consumption templates [0]. My workflow involves an ADF scanner with an Android application, sharing the scanned PDF with Paperless Share [1] and then it's uploaded to the server via API. It seems that consumption templates will enable adjusting tags/sharing settings/permissions of a document at ingestion time based on where it's ingested from.
I use syncthing to sync from paperless data folder which runs on Kubernetes (k3s).
It's a one-way sync. Paperless is the authoritative location. The only reason I back up to Google drive is so that my phone has easy access to the documents I may need on the go.
Personally, I think it isn't really an improvement over Google Drive. Drive offers so many more features, an office suite, integration with many other Google services, etc.
That said, I don't think Paperless is supposed to fill all those gaps. For me, its sole job is to make scanned documents searchable (from anywhere with Tailscale) and durable (with encrypted off-site backups). Having this isolated from a Google account with already too-far-reaching access is a benefit in my opinion.
Edit: rereading the context, I think you were referring to how I used Google Drive before Paperless. In that case I just stored scans in Google Drive. I struggled to organize consistently and search was lackluster. Paperless improves on these, but also is much more hackable. It's easy to set up post ingestion scripts, backups, email ingestion, etc.
One feature which seems to be quite a nice improvement (speculating as I haven't upgraded yet) is consumption templates [0]. My workflow involves an ADF scanner with an Android application, sharing the scanned PDF with Paperless Share [1] and then it's uploaded to the server via API. It seems that consumption templates will enable adjusting tags/sharing settings/permissions of a document at ingestion time based on where it's ingested from.
[0] https://github.com/paperless-ngx/paperless-ngx/pull/4196
[1] https://github.com/qcasey/paperless_share