IMO the "sales/businesses" magic was they billed a high-ish hourly rate for every single minute from start to end of the task however their assistant defined it from their perspective, even during the downtime waiting for stuff to happen while they made a few phone calls and outsourced the help to either occur or get set up. This is not expensive for stuff that they can set up fast from start to end, but could adds up a lot if the assistant needs to babysit a multi-hour process for you, IIRC.
It's possible that other people had other experiences. But I don't think they were starting a clock, doing stuff, then stopping the clock when just waiting for responses from third parties. It was more like start clock, get stuff done until it's all done or set up with no further input needed, then stop the clock. Which is ok, but is not the real magic I originally assumed might make it really efficient as a user (and efficient as a task-orchestration assistant).
The real magic was you interfaced with them simply, by text message, to achieve whatever the goal was, after signing up and being "accepted". The simplicity and flexibility of what the assistant could do, so long as you could pay the bill (whatever they outsourced for you plus their own charge), was what it was worth.
Go to web page, put in phone number and billing info, and agree to the terms/rate. Get magic # to text when you need assistance.
Text # when you need it. Clock starts. Get help squared way. Pretty low effort, they could help with a lot.
I don't know what the tech was in the background, there was nothing magic about it AFAICT. Maybe Google Docs/Sheets. Or, an Asana instance + Wiki + Slack could take care of some assistant doing a task and documenting it for reference, building knowledge of how to get what done. You could use the Issues in Gitea if you want open source, I guess.
As I understand it, Magic the YC company thought they could collect data on what people need and automate the common stuff but I remember reading that that never materialized and they pivoted. Frankly the current offering looks more complicated now at https://getmagic.com/how-it-works/ and truly the magic as an offering to the customer was the simplicity and flexibility.
So for the OP, offer a single SMS number your people can text to get answers or get something done, hiding all the operational detail whatever it is. Obviously, SMS is insecure, so whatever your SSO chat system is at work would be the replacement.
Or a single QR code to get started with the "do anything" chat assistant, and equally strong branding.
But a simple, familiar, "do anything for me" interface was the idea.
I'll say this, to Magic's credit. They helped me get sh* done that I was really putting off and was really too focused on other things for, and that I needed some help just getting done. And they got it done for me. Thanks, YC and Magic. It's still a good idea.