There is a term for this called "sandbagging."
> I don't feel what I'm doing is ethnically wrong, because the company is evidently pleased with my current productivity, but I find it unsatisfying and like a waste of my time on earth.
Sounds like you have a motivation and procrastination problem. Pleasing someone or some organization != ethics.
> The dev tools, docs and tech debt impart such a slow iteration speed
Help streamline how the dev tools are used. Tools alone don't solve for much, they need a solid and frictionless process to follow. Document that process to help yourself and your team. Find some common threads or repetitive issues in the tech debt and fix it without waiting for someone to ask you to fix it. Those kids of work may even help get you promoted and open up more interesting projects.