I wish FFXIV had in-game boss adventurer guides for old content.

[Jeeqbit]

In-game my dude. Because then you can also "Try On" the item in game.

I dont enjoy having to hunt outside sources for glam pieces that exist in the game

It would be nice if all the lodestone features were in the game. But SE seems to prefer website versions of them. But it is still worth mentioning that SE does have these features officially, regardless.