Google's not going to add a feature to Google Chat just for the sake of making it the same as other apps, or to make it more convenient to move files, when Google already expects your files to be in Google Drive and working on them there.
Maybe once you've explained why these files need to be somewhere other than Google Drive then Google may see the benefit in adding the feature. Why would you want to upload/download files in the first place when you'll be working on them in Google Drive anyway? Or, to word it another way, why are these files not living in Google Drive and only existing there? If they are on Google Drive to start with, and that's where they should only be, why are you needing to upload and download files? You appear to be trying to make Google Workspace fit your old working practices when you should be changing your working practices to fit Google Workspace. I understand your point but it's not how Google Workspace works or how Google intends you to use Google Workspace.
