Hire for judgement and coordination; use software for repeatable rules. Many administrative problems need both, but the order matters. Buying software will not resolve work that has no clear owner, and hiring an assistant will not automatically repair an unreliable process.
Look at the work, not the job title
An assistant may be appropriate when the workload includes chasing incomplete information, coordinating calendars, organising priorities and deciding when to escalate. A tool may be appropriate when the same trigger should produce the same permitted action, such as sending an appointment reminder.
Before choosing, list a typical week's tasks. Mark which require context, which follow stable rules and which are unnecessary. Remove unnecessary work before funding a faster way to do it.
Compare the whole cost
For an assistant, include onboarding, supervision, access setup and cover arrangements. For software, include setup, subscription, integration maintenance and exception handling. Do not compare a software subscription alone with a complete staffing service.
If the work is variable, start with a narrow role brief and documented decision limits. If it is repetitive, trial one automated step with a person responsible for failures. If the workflow is unclear, define it before doing either.
A useful decision question: would a competent person still need to investigate most cases? If yes, human support probably matters. If no, and the rules are safe and testable, automation may be the stronger first investment. Review the choice after real workload data is available.