>In case of cameras there are sdcards that are wifi enabled, and also newer cameras should support wireless transfer - isn't that easier and faster instead of pulling out the card?

No, because transferring 1TB+ of data from your camera over the crappy built in wifi chip is a much worse user experience than just plugging in an SD card. Lots of cameras also require you to connect to the camera's hot-spot, which means while transferring that data you are not on wifi. If you're just sending a few jpegs over, fine, wifi is great, but for people to whom the "Pro" moniker actually matters, it's a big deal.

Dongles are fine for sure, but having a slot built in is better, and there's no real reason not to have one other than "aesthetics"