I've been wondering about how the institute manages to produce synths with the very limited amount of resources left in the commonwealth but primarily why they even bother. Granted I haven't completed the game yet so I don't know everything there is to know about the institute.
To me it seems that they need synths to perform cheap and dangerous labour. Why do they use these very technologically advanced - and I'd imagine hard to produce - robots for these tasks when they have a great source of cheap labour living above them? Generation 3 synths are indistinguishable from humans so they need food and living quarters just like humans. You could argue that humans will never be as loyal to the institute as the synths are, but the existence of the railroad faction shows that (gen 3) synths' brainwashing doesn't always produce the most reliable results either.
In summary: why does the institute bother with synths when there are humans to perform cheap labor instead?