While you're not wrong I want to point out that you generally don't get the opportunities to practice staff-like skills until you've proven you can do the 'boring' work too. The system does incentivize performative leadership, but only for a relatively short amount of time in your career, so I don't think this is a huge deal.
Perhaps in some cases, but the ones I worked with pre- and post-promotion didn't really change what they were doing over that period. What I'm saying is that titles are fluid, not fixed, in meaning. They can be inflated or deflated according to an org's mood.
Because they already have the title of staff, and now their success is the team's success, so they are okay with doing boring work.
However, this will not get them to senior staff.
If you are not a staff and want to be promoted, this isn't the way to go.