If any Western aircraft are supplied to Ukraine, it will be years too late to make any difference. The current operation to attempt to liberate some Ukrainian territory is hamstrung by lack of air support - aircraft should have been delivered a year ago, instead of (at best) many long months from now. If any Western aircraft finally do show up in Ukraine it will be far too late to make any difference, and empty speculation about what difference Western aircraft "could" make in the conflict is as relevant as wondering what would happen if Ukraine could invent time travel, teleportation, or the Hogwarts Sorting Hat.