Not at all .. I would think that it weakens it. As you've noticed, it's only making a few flowers every year and I bet it made lots of flowers the first year. Being in a pot which restricts it roots is not helping it either because it also restricts the size and growth of the whole plant. Let yours make seeds.
Datura innoxia is a sprawler, it likes to stay low and spread out. I just took this picture of two of my plants ... you can see, both are loaded with buds.
