Speaking from Europe: after school is literally the most convenient time to practice for everyone involved too. And while sports are in non school clubs, some of them are indeed quite involved. Some are 3 times a week, others 1 time a week, but competitive ones are 4-5 times a week or more. By more I mean including weekend and sometimes morning practice. I know kids that have these amounts of sport now with dancing, soccer etc. I did swimming and we had 3 times a week morning practice back then.

I kinda feel like this is one of those situations where Americans think their system is exceptionally inferior ... in ways that are not actually that much dissimilar to what other countries do.