KingdomHearts-Notable-Game-Timeline:
           BirthBySleep(BBS) ->  I  -> ChainOfMemories -> 358/2 Days -> II -> Dream Drop Distance > III


Kingdom Hearts and Final Fantasy ?
An unlikely combination, that used to work...

Most people probably got into the series due to its conception in the early 2000 days, with KHI.

Its successor, Kingdom Hearts II, or better known by the fanbase "Kingdom Hearts II Final Remix",
is probably among the best known games of the entire franchise,
oddly enough being better in most bases as it's well famed predecessor.

Whatever your entrypoint into the series was however:
358/2 Days was most likely the last "real" game to stay true to the franchise.


Even if you detested the "OrganizationXIII" antics and thought they were "anime-y" and "annoying",
if you managed to get through KHI, KHII and KH358/2 you most likely changed your mind after these..
(Sidenote: KHI and KII were still developed by the famed "Team Tokyo" which was disbanded after KHII,
 for profit maximization.358/2 was developed by h.a.n.d. - a very capable developer that always managed to work best - even with limited hardware as the DS, Most other titles (especially BBS and III that fell very short - quality wise, by Team Osaka) failed to impress

Sadly the series direction in story telling took a sharp turn for the worse with the arrival of Birth By Sleep.
Not only was unnecessary lore tacked on (infront of KHI, no less) but new character far outside the current universe were introduced(Those being Aqua, Ventus and Terra).

The plot suddenly started to revolve around a person only mentioned in passsing prior (Some Xehanort Chap),
when before the nemesis (or allies if we're talking 358/2) were merly a easy to grasp Organization (of max 14 members)

It doesn't help that numerous mobilephone spinoffs diluted the mix even further.

The final coffin nail being KingdomHeartsIII itself.
Being delayed for several years and getting out of development hell just making the 2019 release date...
Feeling unpolished and underdelivering on any front.
- In fact, it was so bad, that the "Critical Mode" was delivered via patch, and a later -costly- DLC ( Re:Mind )later had to be added in post to the game...

Bottomline:
All in all Square Enix and (their current inept dev team) managed to destroy a unique and even sometimes - lifelike Gameseries.
All for cheap cash-in and profit maximization on cost of storytelling.

At this point the only strong point the series has, is the one it had all along:
Its composer. Yoko Shimomura
(And we haven't even touched on the "Gameplay degradation" that occured past 358/2...).

A real shame.

Guess "The Heart" wasn't the guiding Key after all.
Or as Axel would say: The [SquareEnix/Kingdomhearts] [we] once knew is long gone
PS:
KH is such a convoluted mess, cause it cannot reboot each entry like FF or DQ can (just like DetectiveConan)
That is why question and unanswered BS keep appearing. a cash cow.