maxmax.com converts many Fujifilm cameras to monochrome. It's quite expensive, but probably not more than when Fujifilm would launch a monochrome themselves. Previously, Fujifilm managers stated that a monochrome is not to be expected any time.
As a regular Leica owner (those film days) every time I pick up a Leica I'm tempted again. The Q2 monochrome will probably not be an exception. It's not made for people looking for features or value-for-money (though it holds fantastic value in the second-hand market) and in that respect its hard to compare with other brands. It's just like cars: you don't need a BMW to be happy, but it sure helps 😉 (for those who like cars)