They are competing for blockspace even with Segwit. Not that it would stop spam. Please do research.
with a discount, please do some research
normal transactions also get a discount
A normal segwit transaction is 60% witness. A spam is 90% witness or more. This makes spam cheaper per vbyte. But I think you know this you're just being argumentative.
after actually examining some of them, looks like a lot of inscriptions are 99% witness data.... so. yeah.