The number one goal of a UFC champion should be to hold on to that belt at all costs. If that means fighting “boring” so be it. Better to be a tiresome titleholder and collect the champion’s compensation than to receive the more humble check of an ex-champ.
In his most recent disclosed payday as champion (UFC 263), Israel Adesanya earned $500,000. Bloody Elbow’s sources also note how his current deal actually guarantees him a few million dollars per fight while he holds the belt. It’d be a completely difference case and would fall significantly lower once he loses that title.