well brat, the future is just a thing for prophets, i do not think any one can predict well what could happen, but looking at the past i can say the following.
Based upon history, the first thing to die in war is truth, read the accounts of air to air battles in Korea or Vietnam read Russian, chinese sources and american and you will read so much contradictions.
each side in war claims what ever they want, russian sources declared MiG-15 was much better than the MiG-15 portraited by US historians,
in fact in Vietnam they claim when MiG-21 faced F-4 the MiG enjoyed a better kil ratio of 2:1.
Но при столкновениях с более легкими МиГ-21 F-4 начали терпеть поражение за поражением. С мая по декабрь 1966 года США в воздушных боях потеряли 47 самолетов, уничтожив при этом лишь 12 истребителей противника
The other thing is what airplanes are downed and upon what conditions.
Take F-15, it faced mostly MiG-21s, Su-20s and MiG-23BN (the MiG-23BN is the attack version of MiG-23 without radar).
F-15 in fact only downed very few MiG-25s and MiG-29s and also few MiG-23 fighter variants (some MiG-23 fighter variants were downed by fleeing iraqi pilots)
Yes it killed MiG-25s and MiG-29s, but when it faced MiG-25s the Russians claimed some F-15 were donwed, and when they faced MiG-29 particularly in serbia in 1999 the serbs were flying MiG-29s with low maintainance and without AWACs and outnumbered at least 6-10 to 1 with outdated avionics and missiles not corresponding to the latest MiG-29M or MiG-29SMT availiable in the 1990s.
Have F-15s and F-16s been donwed yes they have but all are said been downed by SAMs or AAA by the US, while Russian sources even claimed F-14s, Tornados were downed by MiG-29s and MiG-23s .
4 октября в бой впервые вступили и новые сирийские МиГ-23МЛ, в относительно короткий срок сбившие с "сухим счетом" два израильских F-15A. Несколько позже они, также без потерь, уничтожили еще один "Игл" и один "Фантом". Эффективные ответные удары (не в последнюю очередь - удачные воздушные бои МиГ-23МЛ против F-15A)
I do not think it will change in the future, all sides will try to lie and cover losses, perhaps we will see a few kills that can be confirmed, perhaps the sides will be well matched, or perhaps you will see air forces outnumbering and being better equipped than their rivals no one knows.
If F-22 downs Su-34s J-10s or Su-35s perhaps one or two PAKFAs or J-20s every one in the west will say like F-15 the best fighter of the world.
when in reality F-15 is more or less a match for MiG-29, slightly superior to MiG-25 or MiG-23, inferior to MiG-31 and Su-27.
Mig, lets stick to the hard data, every one in the West recognizes that the Mig 15 was an outstanding A2A platform, superior firepower, climb, and turn rates, bested our best in the early Korean conflict, finally to be countered by the F-86, which found the Mig to be a handfull, but with superior tactics and training the F-86 became the dominant aircraft.
The F-4 was designed to employ air to air missles, it had no internal gun, it was heavy, and it did not like to turn, and yes the Mig 21, was a superior A2A platform, although hard data suggests that your kill ratio is just KRAP.
Propaganda will get you killed, especially if you believe some of the nonsense you quote, and not everybody lies, in fact the poor showing in Vietnam, spawned the F-15, and later the ATF. The F-15 is quite capable even today, and would likely prove a difficult "kill" for any of the above listed competition, and to date the J-20 and T-50 have yet to enter production and are not a factor. In fact good money says the F-15 will defeat all of the above, due to superior training, tactics, avionics,and weapons. That many F-15 pilots chose to stay with it, says more good about the Eagle, than it does negative about the Raptor. Thats why I would be very carefull about your sources, quoting them reflects on your own credibility.