Shift your focus from building to learning
At Noorderwind we are already saying for years: stop with the focus on just MVP's and start with the RATs (Riskiest Assumption Tests)
I think it is a false dichotomy.
The tests if done right, boils down to using evidence from objective reality to know if an assumption is true.
In practice, unless you are testing feasibility or viability, my assumption (🙉) is that most of the validations done as Riskiest Assumptions Test is likely to be subjective and measure "man-made reality" as opposed to "metaphysical truths" about why people made choices related to desirability. Most of them are epistemological errors.
Evading the facts of reality is not an option anyway for building a rational business.
The Riskiest Assumption here is this -> "Running tests that don't directly measure if customers love the product will let me know if customers will love the product if I build it later". After all, the job of a high-growth startup is to "make something customers love" not just something people will pay for.
Recently, I have concluded on a Startup Methodology -> build things that I will be a fanatic paying customer of. And if there are more people like me among the 8 billion who are fanatic paying customers, I got a product customers do love. And as a result, a potential "rocketship". If not, I just built tools to scratch my own itch. I win either way.