Whatever shit tier RU MIC/performance has been, it has manage to consistently defeat or mitigate what US+EU has thrown against her. Which includes highend gear like PAC3 MSE. Meanwhile half the reason RU had a hard time was due to facing UKR's abundant legacy USSR systems. At this point it's not unreasonable to dismiss everything in EU arsenal as wunderwaffe tier especially without US support. Including F35... which even if US doesn't restrict usage against EU-RU scenario, could still be borderline paperweight without US tier ISR.
People also forget NATO fought a much shitter/temu RU in Yugoslavia where NATO threw everything at even more legacy soviet systems. All of the awacs, prowlers, F117 barely chiped away at 20% of Yugoslav anti air, something like 700 harms were fired and destroyed less than handful of SA6 batteries. Hard to argue EU part of NATO has better military capability than 20 years ago.
IMO there's a strong chance US would heavily restrict/limit F35 operations against RU. Because one shot down F35 by S400 let alone anything shittier completely evaporates narrative around 5th gen (and what that entails for IndoPac). They'd rather see RU hit F35s in hangers with standoff munitions because at least they can point to JP and SKR and say, see, you need to build harden air shelters.