Child accounts don't fix the problem that it is a shared device.
I've never considered creating a fake child account for business use, but I have tried to create some fake Apple IDs for shared devices, so I didn't need to use personal credentials. Unfortunately Apple has blocked these fake accounts from accessing some services, so I had to fall back to using personal accounts.
Especially for the literal kids, use a child account. But also use a child account for the work machine so it can use your apps but isn’t your personal messages and photos.