Technical expertise is very rarely where the core value of a product comes from. If you're really pushing some boundary and just have a better technology product, like original Google or ChatGPT, then sure, tech is your special sauce.
For 99% of software businesses, the tech can cause the business to fail but its almost never what makes the business succeed. Things like customer development and sales are actually far more important.
Its hard to build a well-architected web app that scales, but theres many people who can do a reasonable job at it. But translating that to business value is much harder.
Theres many people can build a React project in a week, fewer who know how to turn that React project into money. That should be self-evident on a site full of people who know how to make a React app, but begrudglingly work for others because they dont know how to turn a React app into money.
The thing about "the business guys" is most of them are actually pretty bad at the business side. And a lot of developers are actually better at the business side, because they have more relevant experience.
The "business guys" get their MBA and learn about merges and acquisitions for billion dollar business and do case studies about how GM optimizes their supply chain, information that's useful in some contexts but mostly entirely useless when it comes to getting your first 100 paying customers for your SaaS.
The developer is actually more likely to have the relevant business skills since they're more likely to have put some sort of SaaS on the internet and tried to get users for it, even if they failed.
I was on YC cofounder matchmaking for a while and was inundated with "business guys" who were just bad at the business side. It didn't bug me that they were non-technical, but their non-technical nature led to some bad business planning. For example, one guy who worked in VC wanted to make a GMail / Superhuman competitor oriented towards VCs. I suggested we start with a Chrome extension for Gmail, he insisted we build an entirely new email stack from scratch for the MVP.
Making a realistic plan is part of making a business plan and his lack of technical acumen made him bad at business.
If someone came to me and said, hey I have a super pared down MVP, it's just 4 screens in Figma with a minimal data model, and I have 100 people who I showed the Figma screens to and they signed up to pay $50 a month, can you build it ? I'd be thrilled to pair up with a "business guy" like that but they are far more rare than a good tech co-founder and the business types that get that far tend to offer things like "founding engineer" instead of actual co-founder because they, somewhat fairly, assume that the skills you're bringing to the table aren't actually that difficult to find.
But to recap, my high level point is that the technical expertise is not really the money printer. The money printer is mapping market demand to technical products, which is a business skill. And that business skill is worth a lot more than technical skills. Its just a type of business skill that you find more often in developers than you do in MBA, and so we don't associate it with "business guys". But it's the most fundamental of all skills to make money from software, other than a handful of "exceptions that prove the rule".