Sd cards are for more than storage increases. They're useful for transferring data,( and faster than phone over usbc) and can be a lifesaver if the phone bricks. You at least have your media on the sd. The only reason to remove the slot is for a money grab.
On top of which, micro sd cards give you more storage cheaper...and for those of us not blessed with larger hands and thus stuck with the base models that tend to max out at 256G...give us adequite storage space since we cant type on the larger models.
