I reckon improved empty states are most of the times a Nice To Have, so it really depends at what state of development your product is.

You could work on completing the whole project you’re working on and then work on a “delight” layer to add small details. Usually it doesn’t work tho as the team is fast and fall easy in the trap of moving on to work on the next big thing.

Best thing is having a little time during a design workshop or just through in there some ideas once you are in a sketching/wireframing stage. Get the conversation started, get people to contribute with ideas (especially if they’re PO) so they will become advocate together with you and help you ship small things that make a difference.

You can also justify empty states with pitches around reinforcing the brand (eg: engaging text that just keep the users engaged when nothing happens) or improving conversions (eg: tips on how to use your product to reduce bounce/exits).

Hope this helps