My school does school unis that the team uses and re-uses each year. Kids don't buy their own uniform. I think most school in my area do that, but I can't speak for all of them.
As for all-star, I usually have to buy mine, but I have been on Worlds teams in the past where uniforms were rented, trying to keep the cost down for older athletes (up in Canada, so most of us don't age out at Senior and a good chunk of our Worlds/Open teams are University aged adults paying for cheer on their own.
My gym this year did get new uniforms for everyone. I believe three last ones were about 3 years old, and most kids had outgrown their current ones and they were starting to show the wear, and would have needed to buy new ones anyways. I believe parents requested new ones when they were asked during parent meeting for these reasons. Also, all the open/Worlds teams are needing to make the switch from crops to full tops :( anyway, and since so many of these were old and starting to show wear anyway, the decision was made to go with new uniforms. Pretty sure these will be used for the next 3 years again too.