Why a surface submarine tender does not need AIP

Why use conventional propulsion instead of air-independent propulsion for a submarine tender?

A surface tender has unrestricted access to air, so expensive AIP machinery would add no useful concealment.

A submarine tender is a surface support ship with accommodation, cranes, and fuel tanks. It does not need to remain submerged while supplying its customers. Air-independent propulsion would therefore add expense without solving the problem for which that machinery is intended. Conventional propulsion suits the tender's ordinary surface work.