Everytime I'm tempted to think software is easy compared to hardware, I just remember that AMD is leaving about a trillion dollars worth of market cap on the table, because they haven't figured out a good alternative to CUDA.
Fred Brooks wrote in The Mythical Man-Month that it's harder (more time-consuming) to produce the software that corresponds to a given hardware. In 1975.
Hardware was much simpler and less complex then than now. I wonder how or if that's changed by going from hundreds or thousands of transistors to billions.
ROCm 6 was out Dec 16 (2023), 5.5 was May (2023). 5 was Feb 10 (2022). 4 was Dec 19 (2020)