Even non-technical founders make this error. Everyone wants to believe that "just one more feature" is the difference between make and break.
In my experience reducing features is better to begin with.
This is right approach. Lean. If you don’t have PMF, reduce your features until you find it. Pivot. Maybe pivot again. Eventually you’ll find a market to serve. Just don’t fall into the sunken cost fallacy. Time box your market exploration.
Looking at it from a development perspective the two can mean the same thing: we pivot and so we need to add new features.
However, in my experience the key is to look at pivoting from a non-development perspective. As mentioned in parent comments you pivot to find a product market fit. That entails finding your audience and the problem you're solving for them. Those questions do not require a product, but a human understanding. Questions like 'is it actually a problem they need solving, or a slight convenience?' and 'how are they solving their problem without my product?'.
By pivoting quickly in that space you don't get bogged down by technical issues or challenges that don't even matter, and the real solution might be a week's worth of time.
Thanks for posting this insight, because a typical engineer, if they are worth their money, does not like the idea to launch something "unfinished" or "half-baked" or even "not yet perfect", but the business logic behind the MVP (minimal viable product) is clearly correct.
I think a typical engineer is more likely to want to evolve towards mature software in small steps. In my experience the "complete it, then release it with a big splash" approach is more likely to come from marketing. "We moved the CTA up the page a bit" isn't the stuff of press releases.
Careers that aren't quite so commercialized regularly carry out this process. The obvious example being writers where you may spend months/years writing a book only to find out that nobody wants to publish it. Or perhaps you ultimately just don't like it. I know Andy Weir (of "The Martian" fame) wrote about 75,000 words on his next novel before deciding he just didn't like it, and scrapped the entire thing.