SD 8.0 Specification To Allow 4GB/s Transfer Rates By Leveraging PCIe 4.0

[willmore]

And some flagship phones like Samsung S10/S20 has a memory card slot.

So you can't categorize it as "cheaper" if a phone has a memory card slot, just as you can't categorize black phones as cheaper.

I think he's trying to say that no iPhone has ever had an SD slot, so clearly phone with them much be the cheap ones.