The difference between a business and a career is that a business doesn’t require you to work in it as an employee might. If your business can’t run without you there then it is really just a job, or a profession, not really a business.
If you really want to sell your business someday then you need to stop working in your business and start working on it. Of course, it may take time, but the key is to document every essential task so that an average person(s), without prior experience, could follow your documented system and do the tasks needed to run the business. You are in effect developing an operating system. Most serious businesses have this documentation, usually called an “operations manual“.
A buyer isn’t going to pay for what’s in your head, The more refined and documented the procedures of your business are the more value they will have in the sale of your business.
Make your business system a turn-key operation and then it will be saleable. Otherwise, all you will be able to sell is the domain name as an asset based on the current traffic and backlinks. Trust me, when I tell you that you can command far more for a turn-key business than for just the domain and website content as an asset. You will also be able to market your business to far more potential investors.
There are other benefits to documenting your operating procedures. If you become sick or incapacitated, a family member could step in and run your business while you recover. It also makes it easier to bring in employees and maintain the standards you have established for your business.