Deep-tech failure is usually a clarity problem.
A lot of hard-tech companies are built by very smart people. That is not the issue. The issue is that the company stays blurry: too many possible markets, too many product directions, too many half-true narratives, and too little clarity on what the customer actually needs.
That gap gets worse in deep tech. The science may be real. The engineering may be strong. The team can still fail if it cannot explain the value simply, identify the real bottleneck, and make sharp commercial choices.