Not much different to a doctor reading through clinical trials and then recommending the best treatment based on the use case. They didn't design, develop or manufacture the treatment. They were not involved in the trials. The majority are just expected to know enough to make an educated decision based on specific, individual circumstances.
I want my doctors to use tried and tested treatments. Not reinvent the wheel. A good doctor is one who has a high success rate.
Yet the industry acts as though you're not a good dev if you can't reinvented the wheel from scratch... coz... Ignorance? Ego? Delusions of grandeur?
Hey now... if you reinvent the wheel you can make it your own.
...in a way that no one else will appreciate or understand, necessitating that the next person that comes along will also have to reinvent the wheel...
This holds true no matter how well you try to make it simple, modular (so changes only have to touch the small relevant piece instead of understanding the whole thing), documented by good code comments and multiple external docs for different audiences.
Drives me up a wall. Would be so much easier to just slap-dash whack it together, but I've been the one to come back to something a year later with no clue too many times.