Ordinals are a waste of block space but what can we do? miners just want profits and they'll mine blocks irrespective of what they contain.
Technically it isn't a waste in block space. It doesn't take the space from actual Bitcoin transactions.
It's obviously wrong, Ordinals TX has size more than 0.
I didn't say Ordinals transaction size isn't zero. I said technically it isn't a waste in block space. Why? Because the data isn't embedded within the structure where the UTXO set is stored. It goes to the structure of the block where witness data are stored, which is prunable.
But Bitcoin Stamps is something different, and it should be more concerning in my opinion.