The "quality" of ideas have very little bearing on startup rate of success. Undeniably they have to have some bearing, almost by definition, but they're such an insignficant component of what goes into business success.
I’ve spent a lot of time in my local startup community as well as attending bigger startup conferences. I’ve witness a lot of startups with fantastic execution and highly polished products fail because very few people wanted to pay for their product. Some times no amount of iterating, moving fast, and staying lean can make a business idea work if the demand can’t be conjured up.
Ideas aren't everything but they are important. The crucial distinction is that the initial idea isn't that important, iteration to an idea you can scale (and the execution that follows) is.
I do 100% agree on this, but... I've never seen any discussion of the importance of ideas that wasn't exclusively referring to initial ideas.
So I don't think there's really any risk of overindexing; people who discuss this from a pure ideation perspective aren't talking about iteration - at least not in a way that's realistic. The op talks about "linear ideation" and "restarting flywheels" as what seems like esoteric metaphors for iteration but they're entirely focused on pre-build/pre-execution ideation.