I don’t think, that we should change the current behaviour. In my opinion, this is consistent with the behaviour of other software. Compare the screenshots of Mailspring, Telegram and Nextcloud:
Not sure, how Windows applications behave, but none of the applications that I have tested on Ubuntu or MacOS opened the main window when clicking on the tray icon.
The pattern I’ve seen system tray apps use (and which I really like) is right click for details/menu, left click to directly open.
Right now both left and right open the menu, which is a waste of actions-- and feels very unnatural. Left clicking to open and right clicking for menu is what users are conditioned for with desktop icons and online links/buttons.
I would love to see this feature implemented (and honestly I’d consider it more of a bug than a feature request)