The recently lost file upload feature in the Nextcloud app for Android

AOSP platform dev here. (Filesystem) Opinions my own, I don't speak for Google.

Disclaimer: I don't use nextcloud, and have not looked at their app specifically, this is just a surface level observation from my relatively informed perspective.

My take: SAF would work for this use case, as others have already mentioned.

Google Drive does not have the permissions that next cloud claims Google is giving preferential treatment to, and is delivered via the Play store in the same way nextcloud's app is.

As others have also observed, permissions such as MANAGE_EXTERNAL_STORAGE have been rampantly abused in the past, often in horrific ways.

SAF is a terrible solution for anyone trying to make a cross-platform app (and if you're not then why are you targeting Android as your one platform?), because it doesn't work with native code.

JNI exists, and poor fellows having to write a bit of Kotlin or Java.