My problem with it is how inconsistently things get placed.
App downloaded an image: it could be in the apps main data folder, DCIM, Pictures, Documents, or even a new folder at the base of the tree. Add an sd card and that list doubles as all those same locations exist separately on the sd card as well. (I've had images land in all 10 of these locations before)
/edit missed the 'download' folder. 12 possible locations.
Browsers put em in the downloads folder, but every other app is a wild west for me. Most Reddit and messaging apps I had downloaded to their own little folder.
The only issue I had was some torrent app which stored the files in its own data folder which was inaccessibile to any other app. What use is a downloaded file that you can't open? That's almost like having an iPhone.
(edit:apparently my iPhone knowledge is a bit dated now.)
Even if apps store stuff internally, and other things can't find it, the owning app can give temp access to another app. Ie, if you click on it in the torrent software, it should be able to find the relevant media player etc and open that media player playing the file.
Not defending this though, it's fucking stupid for them to do it that way, but just pointing out it's not totally useless as long as they allow you to tap/open it from within their app.