It's zero net gain at the point of dilution. Owning 10% of 10 million or 1% of 100 million is the same money you simply have even less control.
Unfortunately, rational people may have very different risk tolerances. Founders often see it as I have a company and X money to work with. The next round means I have a company and X + Y money to work with. In that context having a 90% chance of 10 million is often better than a 80% chance of 20 million even if the expected value drops the difference between 0 and 10 million is vastly larger than 10 million vs 20 million. But, smaller stakeholders may not agree with this thinking.
Unfortunately, rational people may have very different risk tolerances. Founders often see it as I have a company and X money to work with. The next round means I have a company and X + Y money to work with. In that context having a 90% chance of 10 million is often better than a 80% chance of 20 million even if the expected value drops the difference between 0 and 10 million is vastly larger than 10 million vs 20 million. But, smaller stakeholders may not agree with this thinking.