Success pretty much requires putting technical people in charge, but that doesn't mean putting technical people in charge is sufficient for success to happen. We have plenty of data over the last 40 years to prove my case. Furthermore, unfortunately, what it means to be a "technical person" is not so simple to define, unfortunately as the easy ways to codify it often exclude the very people who you want involved.
Suffice to say, projects are significantly more likely to succeed when the power in the project is held by people who are competent /and/ understand the systems they are working with /and/ understand the problem domain you are developing a solution in. Whether or not they have a title like "engineer" or have a technical degree, or whatever other hallmark you might choose is largely irrelevant. What matters is competency and understanding, and then ultimately accountability.
Most large projects I've been a part of or near lacked all three of these things, and thus were fundamentally doomed to failure before they ever began. The people in power lacked competency and understanding, the entire project team and the people in power lacked accountability, and competency was unevenly distributed amongst the project team.
It may feel pithy, but it really is true that in many large projects the fundamental issue that leads to failure is that the decision makers don't know what they're doing and most of the implementers are incompetent. We can always root cause further to identify the incentive structures in society, and particularly in public/government projects that lead to this being true, but the fact remains at the project level this is the largest problem in my observation.