I'm not commenting on whether storage expansion or video output is more important. That obviously depends on the person.
I'm saying that while USB-C is an effective solution for video output, and therefore can conceivably overtake HDMI at some point in the future, it doesn't address the same use case as SD at all.
I can use an SD card slot for permanent expandable storage. I can stick a terabyte card in there and forget about it until I need to move it into a new device. USB-C doesn't help with that use case at all. It's actually worse than USB-A, because at least the latter has decent slim fit drives available that will stay in without sticking out too much.
Hidden in your comment is the intent, Apple was selling the MBP with iPhone marketing intentions. You can put more of a $$ premium on storage if the micro SD card slot does not exist, much like an iPhone.
>and therefore can conceivably overtake HDMI at some point in the future,
HDMI will live on forever in the TV space and professional equipment. USB-C / DisplayPort was only ever an effective solution in the computing industry, not consumer / professional electronics.
Same to SD Card, both are targeting to Video / Graphics professionals.
Does USB-C have some fundamental limitation or downside compared to HDMI? As a non-expert in HDMI or the needs of professional TV equipment, that isn't clear to me. The only thing that comes to mind is possibly increased attack surface (BadUSB-type attacks).
I'm of course speaking without consideration for whatever momentum the two solutions may or may not have in the current marketplace.
I'm saying that while USB-C is an effective solution for video output, and therefore can conceivably overtake HDMI at some point in the future, it doesn't address the same use case as SD at all.
I can use an SD card slot for permanent expandable storage. I can stick a terabyte card in there and forget about it until I need to move it into a new device. USB-C doesn't help with that use case at all. It's actually worse than USB-A, because at least the latter has decent slim fit drives available that will stay in without sticking out too much.