It has already been discussed in other places extensively that any fighters that aren't 5th gen will just be liabilities on the battlefield for the #Ukraine.
Of course they can function in other capacities - for defensive maneuvering, for limited recon and direct support on the zero line, perhaps - but we can also imagine them being suckered and baited to their deaths or... pilots heroically intercepting missiles & drones with their jets.
This isn't a gamechanger.