The amount of anime I've seen around here lately about sports makes no sense haha... golf, skateboarding, basketball and now water polo. The truth is I'm not a fan of this genre (I don't really know if it's a genre) because as you say they almost never focus on the sport as such but on the subplots around it. In sport it takes a back seat.
Slam Dunk was the last thing I saw, imagine hahaha but I don't know, I'm seeing what I see at the end.
It's part of this month's quest, so a lot of people here are pretty hyped up to share the sports anime they've watched. I also can't say it's my favorite genre, but it sure is interesting. I'm really curious about sports I'm not familiar with, and since I don't find it appealing to watch the real-life games, I tend to switch to the sports anime. Its drama sure makes things compelling, and yeah—it's a sport anime despite the parts where sports were taking the backseat. I think it's kinda their way to emulate an athlete's beginner life—the physical and psychological struggles—which was pretty relatable for me.
SlamDunk was also one of my favorite anime (despite that it doesn't fall under my favorite anime genres). The comedy there was something else, and although I can't relate with tensai Sakuragi—his journey was interesting and memorable.