I would argue that engineering isn't certifications, exams, or education. Those are methods of quality control, not the act itself.
Merriam-Webster gives the following definition for engineering:
> 1: the activities or function of an engineer
> 2a: the application of science and mathematics by which the properties of matter and the sources of energy in nature are made useful to people
> 2b: the design and manufacture of complex products software engineering
> 3: calculated manipulation or direction (as of behavior) social engineering compare genetic engineering
(https://www.merriam-webster.com/dictionary/engineering)
The first definition is unhelpful as it takes us back to the question of definition, but definitions 2-3 apply to software engineering.
Should software engineering require the same quality control mechanisms as civil or mechanical engineering? Possibly, but that's a very different question.