A single personal assistant can remind to change AC filters and order food to dozens of people. Also, you can have a personal assistant from another country, since we’re talking about tasks like “order food”, “book vacation”, and “remind”

And the cost of finding an agent outweighs the savings of hiring one.

If that were true, wouldn’t there be major agencies/marketplaces, where it would be easy to find vetted assistants? These things tried to happen, they went nowhere, because it turned out that almost nobody wants an assistant.

I think, if someone is not organized enough to create a recurring reminder for themselves, they are probably also not organized enough to instruct someone else to remind about it, and to follow up upon the reminder.