Most of what you wrote is wrong. There are three versions, the F-35A, F-35B and F-35C for the AF, Marines and Navy respectively. The three split a long time ago, so no version is holding any other back.

Where things aren't so good is that the three versions were originally supposed to have over 80% parts commonality. That is now down to something like 20%. That is bad in terms of economies of scale.

All that said, in principle there is absolutely nothing preventing a single, mostly common, design from filling those three roles. Whether the F-35 team has done an exemplary job of doing that is certainly a question.

In terms of sheer engineering, it can be argued that the F-35B is the most impressive of the three versions. It's the first supersonic VTOL fighter ever.