It's unreasonable to expect parents to buy you earplugs. If you know you have sensory issues, you need to pack earplugs just in case. That is your responsibility.
Oh I travel with my own earplugs, but sometimes poeple forget. Nothing wrong with looking out for your fellow humans.
The packs of earplugs aren’t that expensive, and if you can’t get the kids to be reasonably well-behaved it’s your responsibility.