It seems like pillowcases come in two sizes. Barely there, so the tip of your ancient pillow sticks out and you’re constantly fussing with it to get your gross pillow carefully concealed.
And child’s sleeping bag so that you have to tuck in this giant end or it flops around and gets tangled up while you’re trying to sleep.
I vaguely recall from last time I was replacing pillows that pillows have also become complicated so I suspect the two are related.