Some people feel threatened by the idea of training their replacement.
But there are many benefits to doing it.
You can pick someone competent, who will do good work for your company and your clients. You know what it takes to do what you do, so you are a good person to make that choice.
You can delegate some of your tasks each month. They develop competencies and experience, and you free up more of your time for the things only you can do.
You can go on vacation and know that the wheels will stay on.
You can eventually accept a promotion and know that your team will be in good hands.
You can plan for your eventual retirement and know all of your efforts to build your firm and your team will not collapse within a few months of your transition out.
(image generated using Midjourney)