Long story short, FFXV and FFVII:R mark the beginning of a new era of distribution for the mainline series, excluding future MMO titles. Due to the expectations for each mainline title, content is more than likely never going to be self contained onto a single disc again. The biggest pro of this is that such a method can bypass the disc limit in a sense and give players something to play sooner instead of having the long wait while competitors, regardless of genre and quality, are able to put out a title in half the time.

The downside though, is that the experience is going to cost a lot more than what it would have back in the PS1 days.

Example FFXV: Physical copy (60 USD before taxes) + Season Pass (24. 99 USD) + Kingsglaive & Brotherhood (17.99 USD through Target) = ~102 USD + taxes

Kitase has already mentioned in a past interview that each FFVII:R part would be on the same scale as a full fledged game. There is no detailed context behind that though, so it's hard to clarify what he views to be a full scale game. Going on the current meta assumption on the internet that there would be 3 parts involved, that would be at least 180 USD in total. Even if that number is radically inaccurate, the reality still remains that FFVII:R as a whole is not going to be a 60 USD experience.