With either Google or Microsoft, you get a complete office suite for the same price including storage

Right, and that's what Dropbox Paper was probably originally an attempt at working toward, from the opposite direction — "We have Google Drive, now we just need Google Docs."

It should be obvious that "a whole collaborative office suite" is not the kind of thing a regular company can build as an extension play... but somehow some manager inside Dropbox convinced them that direction was possible. At least for a while. Seems they've gradually come to their senses.

For various reasons, I have all three of them. There are some missing things in Google and Microsoft's offerings. Namely:

1. App integration (3rd parties can access to a single folder in your Dropbox, allowing "purchase to Dropbox" directly. Many merchants automatically update the files if they receive updates, too.

2. Auto OCR, incl. handwriting. My old comics which are not English are OCRd, and I can do full-text search inside them, which is very useful for me.

3. Fast, auto transcription in many languages. I needed a transcription of a file recently. All services needed memberships, etc. I did it from Google cloud API toolbox. However when I uploaded the the same file to Dropbox, I saw a transcription button. It produced equally good results in way less time.

4. Send-a-copy (aka Transfer). I don't want to share and try to remember to disable links. My Dropbox membership contains a complete "WeTransfer" replacement, and I use it a lot.

5. Request files. I open a link, people send in the files I need, then the "dropbox" closes automatically. I get notifications for uploads, too.

6. Funnily, a working Linux client.

...and possibly more I don't use or can't remember right now.