It isn't even remotely about the latest technology mattering. ARMAT isn't that great of a missile, It's about the fact that we have three trainers, three interceptors, several strike aircraft and a bunch of WW2 planes, a highly experimental prototype of a helicopter but only ONE aircraft that can do SEAD, and now that we have another aircraft that could have been/was capable of SEAD, and it is believable and possible to mount said weapon, we would love to have it. Especially since it was originally stated to come with the aircraft and show on early WIP screen shots.
If you want to stick to reality then P-40s and 109s shouldn't be in the same sim as a M-2000C anyway, the FC3 aircraft shouldn't exists because they, while realistic, are very far from reality... This is a combat sandbox. . . If you don't want the weapon you don't have to use it or even fly SEAD sorties