Checklists are criminally underused in most industries. It's a testament to how great they work when looking at highly-antifragile contexts: aviation, military, etc., where a mistake can (and often does) cost lives.
The problem is that to use them broadly, you also need to implement operational-level changes. So if I made a startup that helped build checklists, the problem would not just be selling the software (which everyone has to do), but also convincing executives that checklists (even moreso than to-do lists) are worth investing in. The friction a checklist brings, at least in non-ultra-risk-averse verticals, might not be worth it.
The problem is that to use them broadly, you also need to implement operational-level changes. So if I made a startup that helped build checklists, the problem would not just be selling the software (which everyone has to do), but also convincing executives that checklists (even moreso than to-do lists) are worth investing in. The friction a checklist brings, at least in non-ultra-risk-averse verticals, might not be worth it.