If you have any type of structured file format for your Teams, I highly recommend not directly uploading files to chats. Doing this will cause files to appear at the bottom of the general Files tab instead of in their proper folder. Loose files can still be moved to the correct folder location afterward, but it’s an unnecessary extra step that can quickly lead to messy file storage if ignored.
Instead, if you have a folder structure, go into Teams -> Files, find the correct folder (or create one if need be) and upload the file there. You can then hit *Copy Link* and easily share a direct link to the file in chat or channel conversations. This makes it easier to keep files organized and helps avoid copious amounts of loose links.
That said, there may be instances when you might prefer a flat architecture as opposed to leveraging folders. For instance, a flat architecture would work with channels dedicated to simple things like fun work clubs (e.g. “Coffee Club”).