However Cecil could use the Cure line of spells, Esuna and other white magic.
In FFIX Beatrix (A Paladin/Knight) could one-shot you with Climhazzard and Shock... but I don't see the Paladin in FFXIV one shotting mobs.

I don't really see your point... its not like Final Fantasy hasn't played around with classes before. They could very easily give a tanky/healer version of the Paladin.
Plus their armour is literally the coolest in the game.

There is no beefy, tanky healer in this game... that's the issue. You are limited to jobs that take 1-2 hits and die in the healing role.