There are two ways to build a car.

Tired: Wheels, then add a chassis, then an engine.

Not viable until the end.

No feedback on if it actually works, or if any incremental change works, until the end.

Wired: build a skateboard, then make it a scooter, then a bike, then a car.

Continuously viable.

Continuous feedback about how to improve it and if incremental tweaks work.

A continuously viable solution is many, many orders of magnitude more valuable than a solution that is only viable at the end, because it is significantly more likely to produce something.

An excellent post on this: https://blog.crisp.se/2016/01/25/henrikkniberg/making-sense-of-mvp