I found this bike ad which detailed the serial number of the bicycle for sale. I was surprised to see its simply a sticker which is far from the indelible stamped digits and letters on frames I'd seen in days past, usually chromoly or aluminum frames however. I believe this is a carbon fiber frame so maybe those frames can't receive the same treatment without compromising their structure? Perhaps also bike manufacturers avoid the machining costs from printing a unique serial number onto the frame itself nowadays.
Is this how serial numbers are issued for bicycles now?