Magic Bands

What is your opinion on using magic bands? I’m planning a trip (staying onsite, 4-5 park days) for the family (kids are 3&11 years old). Is it worth buying everyone magic bands? I’m sure there’s a personal preference aspect here, but I’m curious to hear what you think…

Edit: Thank you to all who have responded, I’ve read each and every comment and I have a lot to consider!