I wish more brands would follow the Newman’s Own charity model. All profits go to charity, so there isn’t an incentive to hollow out the brand, and the products are a reliable quality at a decent price.
The general problem with this is that starting a business generally requires money, which for-profit companies get from investors. For a non-profit to do it they need to get it from donors, and then your actual complaint isn't that nobody is willing to start a company that works that way, it's that people (e.g. you and your friends) haven't donated enough money to make it happen.
But something that might be interesting is to start a non-profit whose mission is to create value for customers (i.e. produce non-garbage products), and then all profits go not to a separate charity but to increasing the number of product lines the company produces. Then spin the new product lines off into independent non-profits with the same charter so the organization doesn't become large and bureaucratic or suffer permanent collapse as a result of a single period of poorly chosen upper management.
Yes, it’s difficult to start companies like this for the reason you mentioned. Most companies that follow this model come from a singular founder/donor who is interested in charity.
I do like the suggestion of building a charity that spins off nonprofit companies.
When Newman and his friend A.E. Hotchner launched the company in 1982, it started entirely as a joke. They were mixing salad dressing in a barn using a canoe paddle, bottling it in old wine jars to give to friends for Christmas. Once they decided to sell it, Newman felt it would be "tacky" to profit off his own face and celebrity status. Instead, he decided to lean into what he called "shameless exploitation for the common good"
Apparently they set up an organization to help other people do this: https://100forpurpose.org/