While I suppose this isn't as important to some as job functionality, I think there's also something to be said about how the dual job system affected Summoner specifically in terms of job fantasy. Summoners are not and have never been poison mages and while the job has significantly gotten better in terms of actually feeling like a summoner as the name implies, it took a long time for us to really feel like a true-to-its-name Final Fantasy Summoner. I won't say it being connected to Arcanist and Scholar is exclusively the issue, because PS3 support was also a thing back then and doing something like Summon Bahamut in 2.0 would've killed us poor PS3 players (it was a darker time). That said, if Summoner were introduced on its own, I think it would probably fulfill that fantasy far more than it does now even. I mean just look at how often egi-glamours are brought up and how much players want to still summon Ramuh, Leviathan, and Shiva at least, not even including Ravan, Bismarck, etc.