In Europe, soccer is way more popular than other sports, so it has more participants. Also, when a soccer player collapses, more people are aware of it.

Athletes in other sports are also collapsing or having to retire, but less people are probably aware of it. I know that's definitely true of myself. I tend to notice when a soccer player collapses, but I've read articles listing athletes from other sports who collapsed that I didn't know about.