No, it’s more nuanced than just a plural of “doctor.”

Wikipedia goes into more detail, but there are a lot of groups of doctors that are not clinics. Most general practitioners and family doctors aren’t in clinics, for example.

I found this brief explanation helpful:

Most commonly, the English word clinic refers to a general practice, run by one or more general practitioners offering small therapeutic treatments, but it can also mean a specialist clinic. Some clinics retain the name "clinic" even while growing into institutions as large as major hospitals or becoming associated with a hospital or medical school.

The important things being that clinics mainly offer “small therapeutic treatments” or have specialists.

Many (maybe even most) other doctors work at hospitals or offices that aren’t clinics.

Hospitals differ from clinics in the severity of things they can treat. Family doctors and personal general practitioners tend to work in something other than a clinic.