Let's try to bring a little objectivity to this here.

On balance, the AA WO privileges are probably a bit better, but not a lot better. I've traveled long-haul on 20 segments now in my time at Republic, and have gotten business or first on 18 of them and premium economy on the other 2. If you know what you're doing, it's not hard, even with an AAC/SA5X/S3C priority. D1s/D2s are great, and I wouldn't complain at all about having them, but I definitely would miss passrider access to UA and DL. As much as anything, simply having access to the loads makes commuting less uncertain, and therefore less stressful. Of course there are apps like Staff Traveler, but it sure is nice to make an evaluation with multiple airlines based on actual data.

There are lots of buddies and ZEDs traveling that the non-WO regionals with AAC have priority over, particularly to places like South America. Those are all people we'd be behind (or at even priority with) without our benefits on multiple airlines.

Somebody above also brought up the point of IROPS that I don't think was given enough weight. Flights are generally full (particularly pre-COVID), and it's not always as simple as waltzing over to a wide open flight on another airline with a ZED/jumpseat. I am consistently above multiple other people on both United and Delta, and that priority has gotten me where I needed to go where a lower priority wouldn't have.

That's not to mention the priority for the jumpseat I enjoy on both UA and DL, so when IROPS strike and there are a boatload of offline pilots trying to get on I have peace of mind knowing that I have priority over them for both seats up front and in the back.

Again, on balance these types of things don't happen regularly (though lately they seem to be happening more often) and the D1s/D2s would be incrementally more valuable, it's flat out wrong to say there's no argument for why non-WO flight benefits are more valuable. In every IROPS situation I've been able to travel, with a priority that is not at the bottom, on an unaffected airline (excepting widespread weather events, obviously).

I'll also add that in my 3 years I have watched a full flight leave without me exactly twice, both on the United side, and in both instances I caught a flight an hour later. So I think there's a lot of merit to the notion what we lose in priority we make up for with flexibility. Depending on where you live and where you're trying to go, that can be very useful.