How would you find it when in the Toolbox would be a Download Button ?
or on click action ?
Currently, there is no other solution then to call a microflow and to download the file with an activity.
Yes, i know, a download is probably not often necessary, especially without verifitcation. But in this use case it would be nice.
In all fairness, you could have a microflow “ACT_SystemFile_Download” having input parameter “System.FileDocument” and downloads that file. Use that microflow everywhere you need a Download button. Keep it in a General module or Utilities folder. Since every file is a specialization of System.FileDocuments, using that generalized parameter as input will make the microflow useable regardless of entity/file. One single microflow to rule them all.
But yeah, I don't see why a general download button hasn't been implemented yet. If you necessarily need additional logic prior/after downloading the file, you can build it. Similarly applies to opening pages, but that action has it's own button. So let's go.