In India there is a word for this kind of thing Jugaad
Not everyone everywhere are "engineering oriented", and having people with the skills and eye for practical solutions based on available materials, can help tons, and also open up people's imagination for what can be done.
In fact, this goes for northern Europe too, just that more people can manage without home-built solutions and can "buy away the problem" here.
Also, people where immensely thankful e.g. when my quite clever and crafty father managed to repair a water tank tower that'd been broken for months and years, by sourcing some local material, coming up with a repair design, and having local welders create it, etc etc.
I'm not saying you're necessarily wrong, but the realities of a situation guided by those who more deeply understand it can very quickly prune the possibilities that an engineer sees. Many engineers would just get frustrated and give up. Many leaders would become impatient with those engineers.
I think to get people's heads out of the clouds and produce real results requires a very special kind of engineer. That is most likely going to be someone local, not an outsider. One can definitely help on the education side of things for the locals, but I'm not convinced that's where the real problems are. It's more likely political and economic. Not even the best engineers in the world are going to solve that.
As I elaborated on in another comment, it is commonplace to find that people who have little to no education and resources are missing countless opportunities to implement simple improvements to almost everything.
This mindset of "locals know best" is, frankly, toxic. (just think about the locals wherever you live to see how incompetent they are as well)
What is needed is genuine collaboration and communication between people living in whatever situation and others who are fortunate to have more access to information, resources, education on critical thinking etc...
This is insane.
But local people at least have the benefit of knowing their own situations, which puts them ahead of some other rando who doesn't even have that and presumes to know better.
No one thinks that going to someone and offering them ideas is bad. The thing people actually object to is imperialism, and they object to it because it's common. All over the place you see not just governments making rules from an ivory tower, but even well-meaning non-profits providing grants or resources with the requirement that things be done in a particular way with no regard for local conditions.
If you're trying to help someone then you shouldn't need to coerce them. Nobody was ever objecting to the cases where you don't.