Add an NPC to the game that converts Job Points and Mlevel

[Alhanelem]

I fundamentally don't think this is any solution, it would just lead to everyone solo BLU cleaving.

Very much this. Like I said, people will just take the most efficient job, whether they like playing it or not, and use it to reduce the grind for the other jobs.

Think if the game was like this from the beginning. Basically everybody would have been playing the same job and you couldn't make proper parties.

[Dmhlucky]

Bit of an older post, but maybe have a system more like rested exp in 14.
People would still play the easier job to get the rested exp boost, but then would need to play the other job to benefit from it.

It won't discourage people from Botting or Paying for RMTs. Not sure there is an actual fix for that.