Eureka is mostly future proof because of it's unique leveling system, just like Bozja. Level 70 potency changes aren't going to make Ozma any much faster compared to having elemental bonus on your gear, now that's a huge bonus but of course you can't get elemental bonuses on anything besides the chest unless you clear BA a few times.

I always figure they left BA alone since SB because it is rather puggable in the JP data centers, they just communicate and sometimes use macros. I get it was their first community raid to tackle together, hence the warning you get when you talk to the NPC about difficulty. The problem is people want to be carried, don't care, etc. Even if they made it a self-queue, you can imagine many will not bring Eureka actions, mess up add rooms cause of yolo, might not even wait for support fate to clear, or even have people to clear the fate for that matter. So you can't just make it a queue, the support fate requirement ensures it's Hydatos-wide content. In one way they accomplished something great, the other is kind of requires organization because you can't just grab people and clear.

Anywho it's obvious they changed their thinking since then with Bozja CLL/DR/Dal being easier to pug and lower difficulty, they kept the BA difficulty and then some like more instant death, and healer raises don't work aspects for DR Savage and having to be premade to enter.