I mostly agree with you too - however I think there is a subtle difference between an employee explicitly wanting to work these incredibly short shifts, and an employer mandating it.
I.e in your example, where someone wants to work in 30 minute increments and that is the staff member's choice and the employer is happy, then fine.
However it would be unreasonable for an employer to say to a staff member "I'm only going to pay you in 30 minute increments, and after each 30 minutes you can go watch TV, but if a customer arrives when you are on break I want you to run back to work straight away to staff the till, and I'm not going to pay you for the time watching TV".
It's reasonable to ask the Babysitter to work part-time and have fairly short shifts. An example of being unreasonable would be to say that they have to take calls during the day with customers and they will only be paid the minutes talking to customers. It's worth saying the laws here change if you are an employee vs sole-trader, and most babysitters would not be classed as an employee while Uber drivers are.
I.e in your example, where someone wants to work in 30 minute increments and that is the staff member's choice and the employer is happy, then fine.
However it would be unreasonable for an employer to say to a staff member "I'm only going to pay you in 30 minute increments, and after each 30 minutes you can go watch TV, but if a customer arrives when you are on break I want you to run back to work straight away to staff the till, and I'm not going to pay you for the time watching TV".
It's reasonable to ask the Babysitter to work part-time and have fairly short shifts. An example of being unreasonable would be to say that they have to take calls during the day with customers and they will only be paid the minutes talking to customers. It's worth saying the laws here change if you are an employee vs sole-trader, and most babysitters would not be classed as an employee while Uber drivers are.