I work on a Salesforce org where the primary purpose is to manage student data as a CRM. Occasionally we'll have a department need something out of left field. A fictional example might be the HR department asks if they can track employee performance reviews in Salesforce.

Every employee already has a contact record, so we could create a custom object and a custom app to store this. I know that technically it is absolutely possible.

Are there any operational considerations for these ancillary requests? Will this type of app (and dozens like it) start to over-complicate our org and make us less agile and responsive to our core mission (students) in the long run? Would we be better off finding an alternative solution for these one-off requests?