500$ per month each?
With below 50 installs a day?
I've actually studied the mobile market a lot the past 2 months, and these metrics would indicate your game is far above average actually. Very few games are profitable below the top 1000 games.
I think the problem isn't you, it's the market.
Mobile has the lowest discoverability of all entertainment platforms with approx 800M+ players for 1.4+1.2M games.
Other platforms get a much higher chance of discoverability. Steam for example gives roughly 33 times more chance for a random person to actually stumble across your game because there are this many fewer games (and only 150M players).
I'm surprised indies still even bother to try to make any money on mobile. It worked in the earlier 2010s because it was new, but now, only 170 companies in the world actually make real money on mobile...
Have you considered making PC, console or web-based games?
I heard ad-revenues on Kongregate isn't too bad for a low burn rate partnership.