The general uselessness of the middle tier (*S) is where *A falls way behind OW, and also the fact that *A carriers seem to be increasingly circumventing what were formerly seen as alliance-wide benefits (+1 PC for *G) or devaluing *G benefits even for their own FFP members (seat selection for *G on A3).

I understand that OW is essentially a 4 tier system (if you include the Blue/member starting tier) but it's not like BA Silver is particularly hard to get, or OW Sapphire via QR (given how many great J deals they keep pumping out).

As for A3*S, I never imagined that anyone would be aiming to get it other than as a necessary stepping stone towards *G.