Make specialists important, people can choose only 1 profession(crafter or gatherer) to be specialized in, 30% of the every tier of recipes are only craft-able by specialists (tier = 1*2*3*4*) reliably with a discount on the "difficulty" of quality (less hq mats needed to hq),5* recipes only craftable by specialist, no matter the level, also for 5* recipes the skills cost scales, so "out-leveling" them is not an option. "op" skills should be on a "limited" use per each craft, equipment requirements should get a bit higher thanks to accessibility of materia nowadays, make hq materials important for 100% hq. Since gatherers will also have specialization, only specialists can gather "folklore" nodes for their field of expertise.


PS: master books and new recipes which get released should always have a mix of 0-5 stars. This way "casual" crafters also always have new things they are able to craft whenever a new recipe gets introduced.

All this may be somewhat excluding people of the highest tier (5 stars) of crafts, but only if they choose not to invest resources/time into becoming a 5* crafter themselves.

Raiders are rewarded with challanging content and the highest tier of gear available for every currently highest tier of gear. PvP'ers have their own exclusive rewards for those reaching the required ratings and the mode it self has its own challenging aspects and fun to it. Gatherers would have their own special mats to gather (if they choose to specialize in this field) and will be able to sell it lucratively. Crafters their own stuff only they can craft and sell with its own difficulty.

Similar to RL, you can have many skills, but only a very few in which you can excel. In video games, excellency is often tied or shown in a time investment and/or resource investment (gear/melds etc).

So yes, people not prioritizing something, not having the time to invest for it, should not excel.