Yes, I did read your OP. Did you??? Because nowhere in it did you ask about transferring photos instantly.
My first response on this thread stated that my Nikon (a brand which you hate according to other threads) does in fact send photos to my MacBook via wifi. Others stated correctly that their phone can act as a wifi remote for their cameras and that there is a purpose for wifi on a camera.
You state your usb card is fast enough for your purposes when transferring from the camera to a computer.
It is not until Post 17 that you state you want the photos to go "instantly" via wifi. Which gets us back to my initial response that using an external card reader (or even the usb cable) is much faster than wifi.
Again, you have received very valid responses as well as well thought out responses for anyone else who reads this thread, but you have discounted them all, and not until midway through the thread did you even ask the question you really intended.
So yes, in fact, I did read the OP and the ensuing thread. Make sure you ask what you really mean originally and then maybe consider alternate view points from people who have been doing this for 1, 5, 10, or 20+ years.