Certainly there's nothing special about a Raspberry Pi for such purposes, but they are common and inexpensive. I just wish that Pi Zeros were actually available. I've got some old webcams I'd love to turn into security cameras...
Current blades are trucked in one piece (per blade) which is impressive to see. Three of them were parked on I-5 outside of Patterson, California a few months ago. There are a lot of net videos and photos which convey the scale.
Even at the current size they can't get through many highway interchanges and local intersections. The larger ones won't be able to ship in one piece at all.
NASA Wind Turbines approached this scale in the '80's. Unfortunately, this was a previously-unexplored area of aerodynamics for NASA, and they had mechanical stress and noise problems (including subsonics) and were all demolished. I think there was one near Vallejo, CA being taken down when I got to Pixar in '87, and one in Boone, NC, which famously rattled windows and doors.
The art has since improved. I took a ride to the top of the turbine at Grouse Mountain, that was fun! That's the only one I have heard of where you can actually get to see it from the top.
This is starting out with the wrong assumptions.
Design a brick system that can be produced with 3-D printers, and will hold together when fabricated within the tolerances of an SLA printer. Forget FDM, it's too low precision and SLA is already achieving an equal or lower cost of manufacture compared with FDM.
LEGO is manufactured to astonishingly high precision, but I am not convinced that this is the only way to make a brick system.
I wonder how many DJI Phantoms (the Phantom Menace) and other drones decided to fly 4Km away at that time?
Programming through insults and flattery. What could possibly be better?
Well, possibly Java2k.
Blue Origin will eventually have a two-stage rocket that can reach orbit (although they are planning on a much smaller payload than SpaceX for their first iteration). When the booster of that rocket lands without damage, they will duplicate what SpaceX has recently done, although in smaller scale.
Blue Origin to SpaceX at present is a sort of bicycle-to-automobile comparison if you account for the tremendous difference in energy and the application. So, I think there really is an intrinsic difference between the two of them.
If you want to say there's no intrinsic difference, then we need to look at Orbital's Stargazer and Pegasus, which have been carrying small payloads to orbit for years, and there's only been one Stargazer all of that time so there is no question that it's reusable. The only difference is that Stargazer lands horizontally.
We can then look at the B-52 and X-15 combination, in which both stages were reusable, a human was the payload, and we're going back to the late 1950's.
In every non-trivial program there is at least one bug.