Mediocrity should NOT be the standard for players in any content.

[linay]

I feel like the issue is less 'the game's content is not hard enough to force people to learn to play their class effectively and figure out mechanics'. I think the issue is more 'the game's content is really bad at instructing players in their class/job and role'.

Keep in mind that, in a multiplayer game, it does not depend solely on the content to teach you how to play, but players should be helping each other. What the content needs to ensure is consistency in how it displays tells for mechanics such that people can learn more easily from content to content. I think FFXIV has been doing an adequate job in that department, for the most part, especially with newer contents.

In terms of how to do your job well, while there may be an optimal way, reading the tool tips should get you to be able to perform adequately as well.