Why not wake up and realise that you, the parent or guardian, are the one responsible for your the children?
Agree.. yes. However, no matter how much you try to manage three kids at an amusement park. You will always have one that you think is in one place but will wander off. The time (or two) I lost a kid at a park, it was our "home park" which all of us are familiar with and that was when my wife was with me.
Also, the OP noted that the oldest was about 14. That's about when you can give a child a little more freedom to explore. Especially with friends. I remember visiting parks as a teen with school/ youth groups and all we had to do was check in at certain times. We all have memories of exploring parks with out parents.
So lets not be too judgemental and lets share how we can make the hobby a good experience for our kids. In case you're wondering, my kids are 14,12, and 10 and all have had 50 creds by the time they were 10 and will have 100 by the end of May 2020.