This is an absolutely ridiculous take. If my more traditional engineering friend spends a day putting together plans based on existing documentation of parts, is he suddenly not doing engineering anymore? Do you expect him to run off to the supplier with a probe in hand and redo all their data sheets?
If your engineering friends only follow instructions and assemble things then they are not engineering. They are assembling. It takes less to follow instructions than it does to write the instructions.
I'm sure the world's civil engineers will be pleased to learn that, since they already know the tensile strength of concrete and since they use surveyors to map a site, they're merely assembling bridges and freeways rather than engineering them.
You don't need to be a civil engineer to design a single family house. The properties of the common materials like 2x4s are so well known that you need very little training to draw up a print that can be built - you look up in a chart how long a 2x12 can span and so long as you stay under that size your are okay.
Now in a typical house the floor and roof use trusses that are engineered because in those areas engineering matters. Even then they are mostly taking a bunch of trusses already designed and putting their stamp on the system working.
As buildings get larger/more complex though it becomes harder and harder to build the needed charts. Eventually you need a civil engineer to do a lot of calculation (with the help of a computer) because the building is different enough from anything before.
