An improvement, but still worthless complexity for unclear reasons.
No, the reason is actually crystal clear. They don't want players to make the same progress as others, so long as they don't risk flying their own ship or are not as 'senior' ('cause let's face it: Elite rank is a measure of the time you wasted on the game, not representative of skill). In order to model what they think is a "risk vs. reward" mechanic, they take player combat rank and gimp progress, this time at least taking both players' rank into consideration.
Only, they have no fucking clue how to build a game that does not waste their players' time. Wing up, have more fun using your own ship, marginally higher risk, get full payouts. Crew up? You can be the best bloody gunner or SLF pilot in the game, you'll invariably face gimped payouts from severe to now somewhat less severe compared to the time spend doing the very same activity in a Wing. Which means essentially doing the same thing with a slightly different flavor and full payouts instead.
That's one way to tell your players: "
Don't waste your fucking time on this new mechanic we build for you. Go, play that other superior mechanic instead that let's you do essentially the same, only better." That's also one way to waste dev time on developing a shell of a multicrew mechanic. At least winging up for PvE now means not constantly being reminded, that you would be more effective alone.
When they announced their multicrew implementation a couple of months back, I would've considered it a fun coop activity to do for a colleage who recently bought the game and me, even though limited to combat. Now, all I see is a dead paperweight of a feature, that they could've left out of the game for all we care, as we're going to wing up and not bother with multicrew, so in terms of game design and balance, they did at least
some good with 2.3.