What I'm getting from you is that your employees seem unable or unwilling to accomplish their jobs by themselves. You are constantly cleaning up after them, and worry about what's going to happen once you stop doing that. Will they pick up the slack or will they start producing substandard output?

Unfortunately, in my experience, there's only one way to find out, and that's to just disconnect and let things revert to their true output levels. Without you artificially propping things up, you should be able to see what they are able to produce. If this isn't enough to make you happy, well then, you have to do something about that.

I say this because I've been witness to a phenomenon some people dubbed the "cone of influence". Some people were buoyed up by the presence of a much stronger coworker in their area. That person was responsible for helping them accomplish many of the harder tasks they encountered. When that person was later removed from the team, not only did that person's direct contributions vanish, but the remaining team members also lost effectiveness.

It sounds like you might be providing one of those cones.