I think you're confused. The verb form of the word never carried the credentialism of the title. In the same way that "doctoring" never carried the connotation of a medical degree.

Of course the original sense of the noun was "a person who devises things" and shares a root with "ingenious" and carried no connotation of legal credential. That "harm" is more or less restorative to the original meaning of the word.

Are civil engineers, electrical engineers, and train engineers rebranding because of the tech industry?

The word and use of "engineering" predated what you describe as "real engineering work".