one year we had a half dozen, but the last few years nothing to speak of.

thy have been repotted, root and branch trimmed as suggested.

Even though we only average 4 hours of useful sun during the growing season, perhaps these would be better off in the ground.
Since our ground isn't so good either, it would have to be a major dig out and refill of dirt and compost. But what's the point of fig trees if there ain't no figs?