This is a good question. While you do nor need to attend the inspection, it is recommended for several reasons. Attending the inspection allows you another opportunity to walk through the home. Since an inspection can last a few hours, depenidnin the size of the home, this gives you ample time to take measures and look at the home in greater detail than the initial walk through.
This is also a great time to bring any questions you have about the home and ask your inspector. How a system works, or if something looks off about a specific component, your inspector can answer these and many other questions.
This is also a perfect opportunity for the inspector to walk you through how the home functions. I was doing an inspection at a home in Armada and the couple was moving from the Warren. The home I was inspecting was on a well. They couple had city water in their previous home and were not familiar with a water softener and well pump. I was able to show them how the well and water softener system worked along with what the maintenance would be for such a system. This helped the couple feel more at ease with the home having that knowledge ahead of the home purchase.
It’s also a great time for the inspector to point out defects. These can be explained in person to help give better context. The home inspection report is a great tool and can make a perfect “honey do list” but talking about it in person is the best way to communicate an issue. Sometimes reports can look like "doom and gloom" but with a prior conversation putting it in context, it sheds a better light on areas of concern.
Regardless if you can attend the inspection or not, your inspector should always be reachable should you have any questions after the inspection is complete and the report has been issued. You can see what that looks like with a sample report here.