There are a whole bunch of questions on Quora asking why the Amiga flopped. It did not flop. It sold millions of units for years and derivatives of its hardware and software are still on sale today.
The ST didn't flop. It sold millions too, and both EmuTOS and AFROS/Aranym are still around and maintained.
The Archimedes didn't flop. It sold lots, it established a line of machines and OSes that are still on sale, and an offshoot of the company is still around and worth billions and totally dominates the computer industry. Today its CPUs power the Mac, and iPad/iPhone and AndroidAND WINDOWS -- and outsell PCs by about 10x over.
The latest version of the native PC OS runs on Arm chips as well and there are Arm-based PCs on sale now.
Do we say the PC bombed because DOS and Windows 3/9x are dead? Of course not!
Do we say the Mac bombed because it killed its OS, bought one in, and then moved to Intel for 15 years? Of course not!
Did the Mac bomb because all new Apple kit runs on that bought-in OS on a chip design that came out of Acorn? Of course not!
So Acorn's original OS largely died out and has little industry relevance now. So what? So did classic MacOS. So did MS-DOS. So did CP/M. So did original Windows.
Windows today is based on the result of a cancelled DEC OS, Mica, and a cancelled IBM OS, OS/2. The bit MS wrote, MT/DOS, is long gone and went FOSS last month.
Apple OSes today are all based on NeXTstep, and that was based on BSD tech.
But the chips they all run on -- not the only chips, but the best-selling ones -- are Acorn designs.
The Acorn-designed ARMs were released in the late 1980s and very early 1990s. The best-selling designs are the recent ones which do share heritage but are far removed from the excellent work that Furber, Wilson and team did while at Acorn.
RISC OS is a plaything for enthusiasts, a relic if an age where computing was a hobby rather than the corporate monstrosity that it has become.
As a hobbyist and RISC OS user I am fine with that. But Acorn itself got out of the game in 1988 after Phoebe took only 1,400 preorders. Had they continued, Galileo may well have succeeded RISC OS with a more modern foundation.
Bombed?
RISC OS machines sold for some 15 years in the face of growing competition from Windows and Linux.
Acorn chose to shut it down and span off ARM.
Castle Technologies continued selling it and made a new 32-bit-clean version and new hardware for it.
RISC OS Developments bought Castle and made RISC OS Apache-licensed FOSS.
The OS is still alive and in development nearly 40 years after release. You can buy new hardware running it.
You can buy new releases of the OS for original Acorn hardware and emaulators to run its apps on Windows and Mac OS X.
The CPU family is the best-selling in the world and outsells all x86 chips put together by something like 100:1.
Arm sold 8 Billion CPUs last year: https://newsroom.arm.com/news/arm-announces-q3-fy22-results
Intel sold 50 Million: https://tweakreviews.com/processor---cpu/intel-sold-the-most...
Tell me again about how this platform "bombed"?