The number of players in youth soccer is dropping quickly. Due the age group change to calendar year? Due to "pay to play". For the first of those questions, I made the same claim when it changed and my boy/girl twins got bumped up and away from their school class.
https://www.aspenprojectplay.org/tom-farrey-sfia-data-column
"Soccer is now paying a heavy price for underestimating kids’ desire to play with friends. In an effort to develop better prospects for its national teams, the U.S. Soccer Federation (USSF) two years ago began mandating that affiliated organizations down to the community level stop forming teams based on birthdates that fell within the school year. Instead, teams at every age level were reorganized based on calendar year birthdates, in which kids are less likely to play with same-grade peers. That broke up teams who have been playing together for years. Only 14.8 percent of children played soccer last year, down from 17 percent in 2015.
During that period, soccer lost more child participants than any other sport – about 600,000 of them. Or enough to fill every stadium on any given match day during the 2026 World Cup the USSF will co-host with Mexico and Canada. "
