What particular MMORPGs have you all played recently that provides anything beyond the basics of any single job? World of Warcraft was no different. Guild Wars 2 didn't provide anything, nor Rift, nor TESO, nor SW:TOR, nor ...

You are all writing from a level of experience that those new to the game do not yet have, complaining about players with an unknown background in the MMORPG genre.

If you really want to help, provide links to solid materials in the instance chat. Say "Nice job. If you'd like to learn more, check this out." Follow this with a link such as this: [https://www.icy-veins.com/ffxiv/white-mage-guide]

Barring that, provide the information in the forums and point them here. Note that complaining about healers who only heal and don't DPS isn't providing information. It's complaining.