Unless the ONLY sports you care about is in fact the NBA. Otherwise, you'd still need to visit some sports site for updates.
I would imagine this can be easily made sports agnostic? Maybe not... Maybe not all the leagues have a realtime API or they do not conform to the same interface.
Usually a comprehensive app like you are talking about gets built onto until it reaches all sports. Can this not just be the first step?
This can be feature complete for individuals who represent the cross section of NBA and terminal fanatics. Anyone else outside of this cross section, the dependency on the likes of espn.com is still there, and will likely have it open in an adjacent browser.
Expanding your calculator analogy, my point would be akin to critiquing an add only calculator app
Only if you can find the same quality of data feeds in the sports. It'll never be agnostic but it could in theory be generalized so that it's easy to add sports.
But again - data formats.
Looks like this uses a very unofficial API - see the note about AWS IP ranges being blocked on https://www.npmjs.com/package/nba