All patents issued by the USPTO are public though. For you to get a utility patent you need to publicly share exactly what is done. This is supposed to be the reason patents exist in the first place. And in return for publicly sharing, you get exclusive rights for some period of time. In that regard there really isn’t any secrecy
Just because you have the patent does not mean you will win all infringement claims though, as you noted with those Newegg cases
I agree. Patents are only useful in a court of law, and as a deterrent to prevent deep pocketed outsiders from stealing your idea (out of fear that they would lose any infringement lawsuits and therefore a lot of money).
If your patent is crap, like the one that could feasibly be put on a prompt, then there is only the thinnest veneer of protection for your prompt idea, so it's pointless to make one if there is any value more than the 10-30 lawyer hours needed to take it to court and destroy it.
Just because you have the patent does not mean you will win all infringement claims though, as you noted with those Newegg cases