The usability of volumetric lighting on current gen hardware even for a broad use, full screen scenario is unquestionable. Purely by the fact that many games are using it for years now.
Killzone: Shadow Fall is a prime example here:
https://www.guerrilla-games.com/read/taking-killzone-shadow-fall-image-quality-into-the-next-generation-1 starts at page 65.
Crazy what they get out of 8 samples:
https://youtube.com/watch?v=0MilN7jKK9c
Other examples are Lords of the Fallen:
and The Order 1886: