> Compilers "failed" because VLIW is fundamentally not a particularly useful idea.

I think the problem isn’t just that it’s not particularly useful, but that it’s an actively bad idea. It statically encodes ILP that we get dynamically in chip designs today, which means that ILP can no longer react to changing conditions, like literally any core architecture changes as the underlying hardware evolves (or even on the same die, say finding itself running on an efficiency core rather than a performance core or vice versa) or running in an SMT environment in which it is not the only instruction stream going through the pipeline.