If you’re running a startup and haven’t yet found your feet in terms of a product offering, and you’re building your product(s) in such a way that technical debt builds up through continuously layering half-baked on half-baked, it’s indicative that you’re not actually pivoting and not actually evolving, you’re just adding new half-baked ideas to a half-baked system… and being able to do that at twice the speed isn’t going to address the real problem: half-baked ideas don’t make a product, whether that’s 10 half-baked ideas or 100.
My experience is that any company in which evolution/experiments/pivoting is constrained within the boundaries of what already exists because of the sunk cost fallacy has made a grave error at a leadership level, not at a code level. If you can’t validate something without mashing more code into your system, that’s the problem to address.
I’ve seen companies with horrendous tech debt die, and you could certainly frame their death as being a consequence of the tech debt (“if they had just got the perfect system…”) but that assumes the perfect system would somehow prevent them from making the mistakes that got them there in the first place. It wouldn’t. The technical debt is an expression of their mistakes, not the cause. You could dump the perfect system at their feet and they’d be surrounded by garbage again a few years from now.