Why is it that after the sao arc, asuna seems to be not involved anymore? Especially the alo and ggo arc.

I think it's because that the one who made SAO wanted to make Kirito with different female characters every arc atau something like that. Since Asuna was the first she won't be the main character for the second, third and other arcs. I can't say for sure cause I didn't read the buku atau komik jepang but that's what I think.