I have used DEVONthink in the past, and paperless more recently, and only more recently still discovered a real need for this in my life for personal reasons. Since I am at the point of picking a route, I am curious of how you find DEVONthink and its sync needs relative to something like a web app. I don't find myself with an always-on Mac these days, switching my desk between my personal and work laptop, and I would prefer have always access to the files, as well as sharing that access with my wife. I see DEVONthink has a companion portable app, but curious if you use it and what you think of it, though honestly I'm unsure the "scan anything to a SMB share" pattern is unbeatable by features elsewhere.
DEVONthink supports multiple sync methods for the same databases. You could use CloudKit or Dropbox to keep all your devices in sync, and then Bonjour and/or Dropbox to sync between you and your wife's devices.
I don’t share the docs with my wife. I mean, I would if she wanted to, but she’d rather I play house librarian. I currently use DT’s iCloud sync and it works well across devices. Really, I have nothing but good to say about the experience. It just works.
But I’m still experimenting with just plain files in iCloud. 99% of my mobile file access is to pull up scans of vaccination cards and things like that. It’s basically read-only from my iPhone (and iPad while I was using it). My phone’s Files app is full capable of handling that use case for me.