Having educational field trips benefits students by broadening the way the students think and giving them ideas for their futures. When students can experience different surroundings than their familiar terrain, they have new opportunities and may start thinking in a new way or develope a new interest in something. That is just my particular way of thinking.
Being a student currently in High School, educational field trips allow us to take time outside the classroom while still learning about the subject at hand. It also improves other aspects other than education. It increases sociability, gives the students real world experiences, and gives a break from the normal classroom.
I agree that school field trips are a great way to get away from the boring classroom and learn kinesthetically, but mandatory trips can create a variety of problems. I remember from my school that I was always in advanced classes (like grades above), so if my grade ever went on a multiple day trip, it would be difficult to catch up from my missed classes of the grade that did not have a trip. There is also the issue that some kids have disabilities that make it difficult to attend trips. Common children's diseases such as Type 1 diabetes or asthma can be difficult to take care of without parental assistance, and some parents cannot leave their jobs to attend a school trip. When this happens, the student is left struggling to take care of themselves on their own. So to conclude, field trips should be highly encouraged to the student body, but they should not be mandatory for everyone.