Like in my case, the only files I generate on my phone are photos and videos, and these get backed up by Immich, which I can then share with someone by sending them a link to the files/album in question. I imagine normal folks would use iCloud or Google Photos for the same task.
For syncing other files like documents and such, I use ownCloud OCIS, and I'd imagine most other folks would use something like DropBox or iCloud, or even just email or WhatsApp the files.
For local network transfers of say ISOs or something, I'd just copy them over SMB, which is pretty much universal and doesn't need any special app. Or even just plug in a hard drive, if I'm doing backups.
So I don't understand why I should be using this.
Sending a photo over text message often compresses it, which isn't always desirable. (Not actually sure if it gets compressed when sent of iMessage)
I've also used it to send people photos when we were in places without cell service like on hiking and camping trips.