I think the the 4A are pretty much the best in the world right now (mix in a few others) and could easily take places 1-4 at Worlds in any order. So it is pretty unfair that they all can't get the same opportunity to fight for a world medal.
But what I think might be the hardest part, is being the one left off the team. They are all deserving in their own rights and could all go clean at Nats and I don't know what they would place, especially with judging bias at home. I feel like if the 3A place top 3 at Nats above Alina, they may still go with Alina for Worlds over Anna or Alena. Then imagine having to go back to training the next week and watching the others prepare for worlds while you are virtually done for the season, that just seems heartbreaking to me. Especially if it is a case of them not choosing the top 3, whoever they are, from Nats. Then one of them is gonna feel they were passed over and watch the other one get their deserved opportunity. Idk, I can only imagine how upsetting it will be for one of them and it makes me sad.