When you have a competition labeled as Worlds, that is the absolute correct way to run it - there are many sports that the 5th and lower teams would be better than the top teams from some countries.
The thing with All Star Cheer is that there are a LOT of clubs/divisions and without regional championships {like gymnastics/figure skating} you have a LOT more teams going to Worlds. In most other sports only the top 2-5 regional winners move on to Nationals and then only the top 2-3 at Nationals moves on to Worlds. The cynical side of me believes that there are so many Worlds bids as purely a money grab by the USASF and the IASF.
For both USASF Worlds and ICU Worlds, they should move from Country to Country with a hosting bid process. Guessing this hasn't happened because the other countries do not have solid national-level infrastructure, yet. Sort of surprised Canada hasn't been a Worlds location.