Yup. All I ever found was freeloaders who don't put in nearly the same effort. Serious business people who will relentlessly try to get feedback, sell the product and make deals are pretty rare. But when you have one, it's worth gold.
I've tried to start multiple projects with non-developers, and NONE of them were willing to put in any work whatsoever.
Obviously, I might have been choosing the wrong people, but they seemed fairly accomplished.
I think people don't realize how much building software is boring drudgery (figuring out where to put a button). Maybe they expect it to be immediate wheeling and dealing.
Non-technical cofounders need to start out as project managers, and most people don't seem willing to do it.
It's the same problem with finding developers to work for your early stage startup. Actual good sales people and marketers are in high demand everywhere. Finding one that will be committed enough as you is hard when they are fielding offers from established companies that are much easier to sell.
Why not learn how to market yourself? You may not become the greatest marketer in the world but you almost certainly can be competent in less than a year.
Then if you grow whatever project big enough, you can then just hire someone. And you'd actually know how to manage them with insight into their job.
Specialization & experience are good. So are more people. If finding a marketing or "business" partner for starting your project is your blocker, just learn it yourself.
Sure you could get outcompeted but honestly, if one person gets outcompeted, in almost all circumstances so will 2 people.
A founding team usually doesn't cover all of the core responsibilities necessary to run a company. Between legal, sales, marketing, product, hr, accounting, and engineering, it's rare that the founding team collectively has all of these skills mastered.
I have witnessed this exact thing at several startups. It is demoralizing. Especially when they have >1% equity and you're lucky as a dev if you have >.1%