That is absolutely wrong. See European Patent Office - key consideration is that a patent shall enable the invention to be reproduced by a competent proffeshional. If that is not the case, you can strike down the patent in court. That is the whole point of patents.
It doesn't however require you to disclose exactly how to reproduce it or how to do it cheaply or affordably. That information can be kept as a trade secret.
Part of the reason for patents is that someone else could devise a method of reproducing your patent cheaper or more affordably and undercut you.
In particular the tools to make the things are separately patentable. It is common to make something useful in the lab, and then a few years latter patent manufacturing tools that enable you to make it. It isn't unheard of for a competitor to find a better way to produce something than you and then you cross license each others patents so both of you can produce the thing but nobody else. (before attempting this consult a lawyer - the rules of when you can make something patented are complex)
https://www.epo.org/law-practice/legal-texts/html/caselaw/20...