Is it important to operate in the field? I believe the answer is yes. Field Day is okay, but I believe most field day events do not represent what actually might happen in the field during an emergency.
How does your equipment work in a field environment? Can you hear other stations? Can they hear you? How long do your batteries last until the radio quits? How long does the generator, generate? Can you operate in the cold, in the hot, in the wet as well as the dry? You will never know unless you go out and do it.
Operating in the field can be very different than operating from your home QTH. There are often a lot of distractions while you are attempting to operate. I had a dog try to help me send CW with his nose while at a national forest. People, trees, birds, the weather, all try to distract you from what you are doing. To work through this, you need to practice, just like playing the piano, you need to practice.
Fortunately, for us, practice doesn’t have to be boring. We do not have to practice scales over and over again. We can go out, set up and then try to contact other amateur radio operators. We can try to contact operators who we have never met before, or reestablish contact with old friends. We can target different areas of the country we live in such as try for a worked all states award or we can reach out to different countries for a DX award. We have the choice of using voice, CW, or other digital modes. So much to do.
So grab your gear get out and do it! If you forgot something or something broke, count it up to experience and hope to do better next time. I do not always get out as much as I like, but when I do, I find I have a lot of fun. When I go out I typically only run 5-10 watts. It can be amazing who can hear you. I also like trying new antennas, to see which ones work better than others. And this need not be expensive. Take what you have and see how it does. You may be surprised.