This is the thing that people don't realize about autonomous AI.
It's not primarily about saving money.
Autonomous taxis are superior to Uber and yellow cabs. It's a better experience, and it's far safer. Autonomous cars aren't cheaper, they're better.
When AI agents replace human jobs, any cost savings is secondary. A coding job where the AI does most of the grunt work is superior to a job where humans do everything. It's better for the worker (less tedium). It's better for the employer (consistent style, greater test coverage, security vulns evaluated for every function, follows company policy and procedures).
AI agents done well are superior at call center jobs, screen-based office work, mortgage processing, financial analysis, most business consulting like process redesign, etc. The biggest benefit isn't reducing payroll, it's doing the job faster, with higher quality and more consistency.