Can a company like openAI be worth an estimated 1/5th of Alphabet, which offers a similar product but also has an operative system, a browser, the biggest video platform, the most used mail client, its own silicon to running that product, the 3rd most popular Cloud platform, ... ?

I think that is the recklessness in question. Throw in that there is no profit for OpenAI & co and that everything is fueled by debt and the picture is grim (IMHO)