Re: Not sure the comparison is valid
'Facebook' isn't free if you are using Facebook Workplace, Instagram has paid options as far as I can see, and Whatsapp Business is paid for.
So, no, it isn't 'free'.
Of course I personally think your head needs feeling if you use any Facebook services as a critical part of your business.
Yes, I do use it, and it's necessary for various community activities I'm involved in, mostly due to critical mass.