I have a TrueNAS server at home and thought I could easily connect it to my phone (Pixel 7) as a network drive but was surprised to learn that Android doesn't have a built in feature for that.
iOS/iPadOS does have this to my surprise built in via the 'Files' app.
Or did I just not look hard enough in the Android settings? (I know there are 3rd party apps for this)
It's not built in, but I generally recommend Solid Explorer for that functionality: https://play.google.com/store/apps/details?id=pl.solidexplorer2&hl=en_US&gl=US
There are plenty of third party apps that do this. The integrated file explorer on Samsung devices supports ftp, sftp and smb.
You know what? I never noticed that.
The stock files app is lacking to say the least. Try Material Files and optionally Round Sync which will allow you to access all rclone supported remotes in the material files app.
Which OS do you run? Android just isn't enough anymore these days.
Did you try material files?
3rd party apps are somewhat funny on android since every app is 3rd party on another android os device.
I am connected to my nextcloud and my proton drive via the "built in" files app from grapheneos.