I stumbled upon this strange problem. The following sentence is grammatically correct:
It's better to be miserable and rich than it is to be miserable and poor.
Let's replace the second "it is" with its contraction:
It's better to be miserable and rich than it's to be miserable and poor.
Why does the sentence seem grammatically wrong, or at the very least, awkward? It could be explained as merely bad style, however, stylistic issues are not grammatical issues and are often not awkward either. Moreover, substituting noun-verb pairs for their contracted form technically shouldn't change the semantics of the sentence.
It is more good to be miserable and rich than it is to be miserable and poor.
This is elliptical for:
It is more good to be miserable and rich than it is good to be miserable and poor.
We elide the second occurrence of "good", but removing it leaves a grammatical trace. It's not grammatical to contract a verb that comes just before a trace. Adapting FumbleFingers's example:
It sounds more bad than it is.
This is elliptical for:
It sounds more bad than it is bad.
– Rosie F Mar 03 '23 at 06:13