The point is: there were over 120 fighters in the engagement area. It is hard to believe that only one PL-15 was fired. Normally in conditions like these, a J-10C would fire two PL-15s to “guarantee” the kill. The J-10 may have fired its PL-15s as soon as the Rafale signaled on the radar and then immediately went on the defensive, increasing its chances of evasion. While the Rafale (with a smaller firing range) needed to get closer to fire its MICA – while the Rafale entered the firing zone, the PL-15 was already heading towards it (pitbull) and the J-10 was already on the defensive. By the time the Rafale’s radar warned that a PL-15 was coming towards it, it might have been too late to escape.
Micas weren't in range early in the engagement, and i doubt Pakistani fighters pushed into their envelope just to make things fair (furthermore, RVV-SDs, Astras and Derby-ERs are here). So probably they didn't have chances to be used at all.
Furthermore, i assume all Indian a/c were under strict prohibition to cross(or risk crossing) LOC under any circumstances, to avoid capture. That's where the problem comes - Rafales can use meteors, but we for now don't have signs of it. Maybe rafales which delivered strike close to LOC(AASM ones)weren't even carrying them. Maybe no rafales carried meteors at all, which will of course bring up the question, why.
My current assumption - rafales(and maybe mirages) were in the front, but not so much as vanguard fighters, but more like tried to do Ukraine style insertions for targets close to LOC with shorter-range ammunition (AASM); targets around LOC are numerous, and they relied on higher survivability factor to make it work. They weren't thus in a good position to do Air combat maneuvers. Their role for the air battle was more of information nodes for the archers remaining behind and up high.
Su-30MKIs(archers) - mostly top cover at a certain stand off, with some(remember only 2 sq can carry it!) doing Brahmos launches from the rear w/o any significant exposure to risk.
Mig-29UPGs - reinforcement and/or escort(note how close that K-36DM to the LOC), which basically went hard in to save the force and prevent the pursuit, after things turned bad.
If my assumption is right - the problem was still that the most exposed Indian aircraft(Rafales over Kashmir) didn't carry longest range weapon, and thus were picked off from relative safety; CAP couldn't protect them from behind the way VKS does (by sending FU R-37Ms to whomever tries to engage bombers).