Not usually, and especially not for physical products. An 8 digit alphanumeric serial contains 2.82E13 possible values (which is more than any one company will sell of anything, ever), and it'd be crazy not to use that to store some kind of information like models, series, bins, etc. Two characters allow almost 1300 possibilities, and just three give over 46,000. Our POs have 6 digits, and after over two decades of multiple weekly deliveries, we're still in the 500000s.

To make that random would be a huge waste and also destroy the potential for creating visible patterns helpful within a lot of industries.

Edit: I just thought about redemption codes, which yes, do aim to be randomized have a huge space relative to the issued codes. In those cases, I see what you mean. Serials of digital media are often and intentionally randomized.