In four decades we went from zero, to infinite possibilities and then (de-facto) to zero again, even as the planet is drowning in oceans of smartphone electronic waste.
Back then you would plug your rubber key wonder into a TV and could program the device right away [1]. Think of what it takes to program [2] a smartphone today. Its practically impossible unless you are a professional developer with very specific specializations. Yet we now "own" devices that are infinitely more capable than the ZX, in every possible dimension (cpu, disk, memory, comms, screen, camera, microphone, you name it)
Mass personal computing has been hijacked, sealed up, dumbed down and thoroughly diverted to serve pretty much only one objective (out of the vast range of social and economic opportunities and challenges): consumer tracking and profiling, for the purpose of intermediating online consumption.
We can only guess at what wonders would have developed in the intervening four decades if the original ethos and creativity of the tech industry had survived even in part the onslaught of the particularly virulent type of commercialism that has come to define digital technology.
[1] https://worldofspectrum.org/ZXBasicManual/zxmanchap1.html
[2] "programming" meaning in this context any advanced controls a user has over a digital device, providing agency and abilities to shape its function for their own benefit in ways that are not pre-programmed and fixed by the vendor.