Many drugs are offered via both prescription and otc (i.e. esomeprazole 20mg). i am aware they technically have different indications or directions per the label, but why are doctors still highly prescribing these drugs if they are available otc?

Most OTC meds: are lower dose preparations of the brand dose. Higher doses are available on Rx.

Primarily cost: OTC forms tend to be more expensive, especially if the patient has any insurance coverage for prescription medications. It is not common for insurance companies to cover OTC medications. After a medication has been available OTC for a while (months-years) insurance companies often stop providing any coverage for that medication, even if prescribed.

Same Medication: Whether OTC or prescribed, they are the same medication. Sometimes the meds will be covered by insurance when prescribed, but not when bought over the counter.

OTC, Rx cost: Often the decision to recommend an OTC ( over the counter) medication or write a prescription for the same medication depends on out of pocket cost to the patient.