Minimum item level is still a bit tougher than "item level at the time it was released". That aside, it's a fun thing to do for trials or dungeons, but unless you are a popular streamer, in a huge FC or on a discord specifically aimed for people doing minimum item level runs, getting 23 other people to look into party finder exactly at the time you are at this point in the story is highly unlikely. Especially at odd hours. So while I get the sentiment, I'm pretty sure it clashes with reality of organizing anything like this on a whim, at least in my experience.
Alliance Raids are considered doable by the average player (who likes Alliance Raids) at the time they are released, so I don't see why it should be suddenly so bad to lock the maximum item level in this area. Some people in here are acting like people would ask the devs to make the fights much harder when the demand for a proper level sync is only restoring them to their original state. They did it for Endsinger and it restored it from a snooze fest where the stuff past the tank LB3 was cut off to the spectacular experience a fight at the end of the storyline deserves to be. Yes, it takes a bit longer when you get it in roulette, but it's actually an interesting fight now. And it's still not as difficult as at release (where I played it for the first time) because at least half of the people have played the fight a bunch of times and know the mechanics, so it would still be manageable if someone is new or simply not as good at the game without locking them out.
Without a level sync for Alliance Raids and Normal Raids, you are also actively punishing for people for being late to the party. In a game that prides itself with respecting a player's own pace in playing MSQ etc., a level sync preventing fights from skipping important story or character relevant mechanics (like the scales in Aglaia) is long overdue. Currently someone who just finished Endwalker and looks into the Normal Raid has to fight a big, strong warden of a high security facility and doesn't even make it to LB2, same with other fights. It's not as bad as old Cape Westwind but it certainly has the same vibes. I managed to play all Endwalker fights right at release and it pains me to know a new sprout will never have this experience again. :( Same as with the "OMG A GIANT ME!" moment in Aglaia.
