Currently Confluence and Jira (both cloud version) only enable to "click" attachments.
Unfortunately modern browsers (or is it the Atlassian software?) only offer *very* limited display capabilities. In fact most attachments are rendered more or less unreadable.
So I *really* prefer and was happy in the past to be able to download attachments and to display them in a proper native OS application. Even this might involve M$ office apps 
Unfortunately the easy download (right click, save link as) has been overlayed and broken by the "new fancy Atlassian GUI features".
Aaargh!
Guys: did you read W3C documents once in a while?
I mean this has been defined, standardized, implemented, adopted by millions
of users world wide in a very sound, transparent, consistent, uniform and
generic way.
Only to make Atlassian come and think their ideology of a GUI would be better?
Come on! This is really annoying. Please bring back my web 2.0. I need those
conventions and features to get actual work done, you know? All the new
hanky-panky-itchy-scratchy-clicky-rainbow cream is just standing in the way
and making all our lifes harder.
So, please, sometimes less is really much, much more!
Please remove that blinky, shakey GUI crap and allow us all to go back to
work.