We're blatantly arguing at this point which of the Big 3 could survive today, when I feel like a good topic that may be less divisive (I've jinxed it now) would be: which series do you think did poorly/below average in the past that might do well today?
As already mentioned, definitely
Psyren. I feel like it was too smart and serious for it's time.
Ironically
Kagamigami, Iwashiro's title after that, might've worked way better if it released in the early 2000s or 90s.
The guy really knows his stuff, but never really gets the timing and mood right... :<
Forget old series surviving today. I think the more interesting question is, what modern series would have done better in the past?
Toriko without a doubt would have done way better in the 80's or early 90's, in my opinion.
Possible, but debatable.
Toriko was already rather successful by specifically banking on being a throwback to older times and it's silly gimmicks. That might have given it a strong niche of loyal core fans and curious people liking the different style.
Being in the age it was aping would have made it just another of many similar titles.
As for your question, maybe
Yui Kamio. That series feels very much like an early 90s action-romance-comedy hybrid and the less strict rules about fanservice back in the day might have helped it's appeal.
(Also Kagamigami, as mentioned..)
