That's really cool. The reason all these Meccano-like sets never took off is that they're so fiddly. Unlike Lego you don't just need the beams and your fingers, you need screws, washers and screwdrivers. Taking them apart then becomes a tedious nightmare instead of satisfyingly pulling them apart with your fingers or just smashing it on the floor.
I remember getting a small NiCd electric screwdriver for Mecanno when I was maybe 8. Complete game changer! Still not as easy to disassemble as Lego, but sometimes that was a feature (e.g. when making things that could move it was nice that they didn’t RUD if they fell off the table)
It's true, but, to quote Dr Ben Goldacre, "I think you'll find it's a bit more complicated than that."
Meccano (and Merkur) use proper fasteners. So, you're learning useful life skills with the fiddly bits.
But that also means the joins are much stronger, so you can build working machines that can handle real loads in Meccano.
Meta-but: when you do this, you discover that the thin metal plates are not strong. So, you need to learn to build box section structures and so on, which in itself is a real-life engineering skill which can help if you later go on to building structures from real-world materials such as metal tubing, wood, bamboo, etc.
So yes, the fiddliness is a pain, but it's an educational pain that leads to more learning...
Until you end up with the skills to build multi-meters-tall objects and working machinery.
Whereas Lego doesn't scale up well. Even large Lego sculptures, which are mostly static and unmoving, not machines, must be glued together. But that means you have to do un-glued test builds, get it right, then tear it down and repeat the entire process but with adhesives.
Above fairly trivial level, what Lego teaches is bad practices and bad engineering. Which is not a criticism of Lego! It's a toy and meant to be one, and it's a great one. But building complex machines is not what it was meant for -- whereas that's exactly what Meccano is good for.
