My laptop runs on Linux Mint with Cinnamon desktop (default Nemo file manager). It has nextcloud-client, nextcloud-client-nemo, nemo-nextcloud, nextcloud-desktop-* installed.
Using the Nextcloud app for iPad or Android, I can access comments for each file.
$ aptitude search nextcloud
p caja-nextcloud - Nextcloud integration for Caja
p dolphin-nextcloud - Nextcloud integration for Dolphin
p libnextcloudsync-dev - Nextcloud folder synchronization - develop
i A libnextcloudsync0 - Nextcloud folder synchronization - librari
p nautilus-nextcloud - Nextcloud integration for Nautilus
i A nemo-nextcloud - Nextcloud integration for Nemo
i nextcloud-client - Nextcloud folder synchronization tool (tra
p nextcloud-client-caja - Nextcloud integration for Caja (transition
p nextcloud-client-dolphin - Nextcloud integration for Dolphin (transit
p nextcloud-client-l10n - Nextcloud folder synchronization - localiz
p nextcloud-client-nautilus - Nextcloud integration for Nautilus (transi
i nextcloud-client-nemo - Nextcloud integration for Nemo (transition
i A nextcloud-desktop - Nextcloud folder synchronization tool
i A nextcloud-desktop-cmd - folder synchronization with an Nextcloud s
i A nextcloud-desktop-common - Nextcloud folder synchronization - common
i A nextcloud-desktop-doc - Nextcloud folder synchronization - documen
i A nextcloud-desktop-l10n - Nextcloud folder synchronization - localiz
I don’t have a problem seeing the files, and there is some Nextcloud integration in the file manager - but I have not seen any mention of the comments.