It's yes and no. They're effective when compared to rest of Ukrainian defenses(fighters included), but overall system isn't effective even v key targets(LACMs). Granted, part of it is geography, proximity and completely different level of opponent. But part is just plain lack of ammo and effective sensors.
On the contrary, USAF fighters are so effective, they brought a paradigm shift. Without them, Iranian drone threat against Israel would've been effective (as it frankly was in the past even at far smaller scale and effort).
But F-15E is just a revolution in how everything is aligned on it. F-16(SABR units) and USMC F-18s are not too far behind, and the rest of the world...almost doesn't count when compared tbh.