It hit a sweet spot for everything that basically let this design take over the world of early computing and it was easily composable to larger memory sizes up to a point that was sufficient for the time.
There's a pretty good reason this style of RAM is used on so many machines of the time, in pretty much the same configuration, and that you can pretty much swap RAM chips between machines of this time.
Never liked these 4116s myself due to their multi-supply voltages. Common cause of problems where used (like in the ZX Spectrum as another poster pointed out).
And of course Ken Shirriff is brilliant as always!