I'm assuming that this is because you see yourself running your company for the rest of your life. There are at least two ways that I can think of right off the top of my head that will enable you to cut ties with your investors while keeping them happy with the result.
You can have them sell their shares on a secondary market, which will enable them to get liquidity, but then you'd have to deal with new shareholders. The only other alternative is to buy out their shares in the company through profits.
So, for instance if your company has $100 million lying around in profits, and your investors shares are worth $80 million then you can buy them out at $80 or even at a premium if that's what they demand, and that will enable you to reallocate those shares to employees; namely yourself since you'd then be the largest shareholder.
Not many companies are profitable though, so that's usually not an option for most investors. They also tend to want big exits, which is why they'll pressure you to either go public, or sell to a much larger company.
A company that generates roughly $100 million in revenue likely has less than $10 million in profits. However, because the revenues are so high, the company would be worth roughly $1 billion if it were to go public or be sold to an acquirer.
Assuming that the investors own at least 20%, their shares would be worth $200 million if the company were sold or went public, whereas it would take a very long time for the company to generate $200 million in profits to buy out investors at $100 million in revenue.
I hope my answer has been helpful.