Is this sentence grammatically correct? (Concerned with the usage of "have less to do with")
I agree that it's a bit awkward. I think that stems from comparing "having to do with" and "serving as".
I think "solitude" here has less to do with being a reference to loneliness and isolation, than with serving as a prerequisite for recollection and reflection.
Or perhaps even better:
I think "solitude" here serves more as a prerequisite for recollection and reflection than as a reference to loneliness or isolation