I believe Cage had a massive tax bill to pay at some point which led to him appearing in basically anything he was offered, including what is without doubt the worst film I have ever watched, Left Behind [1]. One review I read said something along the lines of "phoning it in would be too kind a description, Cage is so devoid of effort or emotion in this film he regularly appears to have been photoshopped in afterwards" which really summed it up perfectly.
Having said that, both before and after the money trouble, he made some superb movie choices and put in some outstanding performances - think Wild at Heart, Pig, Unbearable Weight etc. Hats off to you Nick.
Their style of intensity and overacting do have some overlap. They've also both demonstrated that, when they care, they can be excellent and nuanced actors.
But Cage's intensity often comes up as kind of funny or endearing. Leto's overacting is often cringy/edgy or downright unpleasant. Which seems to represent both their personalities too.
https://en.wikipedia.org/wiki/The_Unbearable_Weight_of_Massi...
I think he just likes making films.