Then why do they need to give the technical co-founder 20%, or even make him a co-founder at all? They either have enough privilege and connection that they can bring in serious funding from investors, future clients, or friends/family/fools, - or they don't and their privilege and connections aren't really worth that much. If they did, they'd much rather give them a few percentage points and pay them a salary, capturing all the upside.
It's a broad over-generalization but it's a good rule of thumb. They must have access to demonstrable money and/or power before they're worth an 80/20 split, well above what most random business guys can bring in from even elite universities.
Edit: A decent somewhat recent example is Theranos. No biotech VC would touch them because they do due diligence on the basic scientific viability of their investments, but Holmes and her cofounder were able to bring in huge tech investors from family connection and even get people like Henry Kissinger on their board, who also helped them get more investors. That's the kind of connections that might be worth an uneven split.
They need to pay for the tech then. Hire an engineer and design team. If they don’t have the access to that sort of immediate funding, then I’d struggle to imagine what sort of in-the-bag contacts they could bring to justify such an uneven split.
And that type of person quite often turns out to be a huge over-privileged narcissist who's never had to work hard a day in their life, because of their family and frat-bro connections, and who will gladly fuck you over without a second thought.
