Founders are fantastic for a company in the early stages because of their ability to take risk and execute to make their company successful. That combination will likely never happen again in a company's lifetime, since the ability to take risks and execute decreases as a company matures.
There are only really two goals that early stage founders should be concerned about. One is to get to the point of increasing marginal returns, where every additional unit of their time starts producing an extra unit of output (traction, revenue, or value). This means for every unit of your founder effort, you are starting to increase the output of the company, either through scalable technology, intense hiring, or a mass of customers.
Founders should be aiming to get to this point as soon as possible. This puts the company at a trajectory where there is increasing returns to their effort and the company is starting to crystallize and become its own entity.
To get to this point, founders should be looking for opportunities of maximum leverage. For example, this means finding markets where there are very few players so that the market is starving for a new product or service. Or making their product 10x better in design or innovation than anything else on the market. Or being able to gather a critical mass of customers faster than the competition.
Once there, the next goal is to get to the point of diminishing marginal returns, where every additional unit of time starts producing a decreasing unit of of output. At that point, it's better to have other leadership come in to stabilize the company or hopefully get the the company to another point of increasing marginal returns.