I’m sure there would be people complaining, ‘Hey, why aren’t any of the Scions of the Seventh Dawn there? Why isn’t Alphinaud there? Why aren’t you bringing Alisaie along? Why isn’t Y’shtola there?’ I’m sure we would get those kinds of complaints. So it is really, really tough.”
No, it SHOULDN'T BE tough, if you have competent writers like Ishikawa.
People will only complain if you don't give us a good enough REASON for their absense. If I feel the only reason a character isn't included in the story is because the writer didn't want them there, then I'd be upset (like I was in Dawntrail). If I feel like "ok, that makes sense, and we will meet them again and see how that went afterwards", and then we get to see the result of their work at a later time, then it's satisfying.

I'd rather have my favorite character not be the main focus, but feel like they're still acting like themselves and their absense MAKES SENSE. I feel like they've been getting that wrong since the Endwalker patches...

For example, G'raha's absense during the patches and why he didn't go to Tural. When I complain about it, people think I just mean 'I want him to be there all the time' but that's NOT the case! I just want to feel like there's a reason for him to not be there. Yet, he wasn't called during the EW patches for no apparent reason, even when Y'shtola talked to him offscreen several times, even when we went to the First with instructions from him, and even if Krile appeared during the patches but no one ever asked about him.
Then, he offered to stay behind and not go to Tural "so Krile could go", never got an explanation on what he was working on or what was so important that he had to stay, and then Krile herself was the one that called him back - so why wasn't he able to go before, but now he is and I still don't know what he was doing?!

For any other character, that could've worked better, but G'raha made us promise him adventures. His main wish as a character now is to go on adventures with us. That's why he wanted to go back to the Source. That's what he promised us in Ultima Thule, and the writers never mentioned that ever again. THAT'S why it's upsetting that he wasn't there, not just "oh I want my favorite there". If he was so easily giving up adventure with us, then he must have had a really good reason to stay behind, right?! Apparently not, and I feel like they're not writing the character right when they do this.

I talk about him because he is my favorite and the one I know best, but I'm sure everyone else has their own favorite Scion that they can tell what their current goals are, and if their actions don't fit their goals and ambitions, that's much worse than simply not having them there.

Also, ShB had almost all of them in good balance and done perfectly, but before that, we used to focus on specific characters at certain times, and it worked really well. Why is it a problem now? They used to do that already!