One organization, six separate search markets
A center running outpatient mental health, an intensive outpatient program, medication management, adolescent services, detox, and residential substance use treatment is working six markets with six different searchers. The person looking for a therapist who takes Medicaid and the person looking for detox share nothing except your phone number.
When those six live on one services page, that page ranks for none of them and converts poorly for all of them. Google needs a distinct page per program to understand what you do, and the visitor needs a page that answers their question without scrolling past four programs they do not want.
Add locations and it multiplies. Program pages, location pages, and program-at-location pages, each written once and written properly, is a large body of work. It is also the work that moves call volume, and the work a generalist agency skips because it does not fit a monthly blog retainer.