> Gradual growth inevitably results in loads of technical debt that is not paid off as Product adds more feature requests to deliver larger and larger sales contracts.

This isn't technical debt, necessarily. Technical debt is a specific thing. You probably mean "an underlying design that doesn't perfectly map to what ended up being the requirements". But then the world moves on (what if a regulation is added that ruins your perfect structure anyway?) and you can't just wish for perfect requirements. Or not in software that interacts directly with the real world, anyway.