It’s kinda silly not to have serial numbers anymore. Just for tracking purposes, because bad batches of parts come in and may go out before being determined to be questionable or unsafe due to metallurgy, heat treat, dimensional issues, etc. that would let a maker know that guns X to Y may be problematic. Also for tracking warranty as other mentioned.
That said, I only own 2 currently and one is serialized and the other is not. The TC is, the older CVA is not.