In the US, ESPN somewhat built its reputation on having some of "all" sports, in part because when the channel started it was much easier/cheaper to fill 24 hours a day on cable with imports and non-traditional sports.

That still seems to mostly apply. In the US on Disney+ the US sports are often front and center, sure, but you can still scroll the list and get European football matches and some Aussie Rules Rugby and Cricket all kinds of things that people don't necessarily think US sports fans would watch. I think part of what ESPN realized, too, is that even regional sports can have global appeal with the right marketing or the fact that not much else is being played in that moment.

ESPN is also still often the home in the US of things like the Scripps National Spelling Bee and various Poker and Chess championships. This was famously mocked in the comedy movie Dodgeball with that movie's climactic Dodgeball championship happening on ESPN Ocho, the fictional 8th cable channel for US ESPN (which had 3 channels at the time). That joke has come full circle in interesting ways as ESPN has roughly 7 cable channels today and intentionally uses the "ESPN Ocho" branding for weirder/smaller audience championships even though the number of people that still remember the comedy movie Dodgeball is shrinking and people don't remember why it was a joke.

I don't have cable or Disney+ any longer but, as someone who played rugby in school and still have an occasional interest, I find it's difficult to find in the US on TV.

Honestly, in these days when pretty much everything is sourced from individual production companies and showrunners, it becomes pretty clear that while some studios have their own brands/budgets/priorities/execs/etc. there's no magic formula to getting it all right. It's been tried before and will be tried again.