"meaning some committee must have thought this would be important for the future (of the internet)."
Have a read down the entire standard [1] with an eye to that. There's a number of codes that are useless (some deprecated), and a number of other codes that I feel uncomfortable calling useless, but compared to how the web evolved, certainly aren't working the way the initial designers intended. 406 "Not Acceptable", for instance, is for when the client sent up Accept-* headers that don't match anything the server offers. That's technically usable, but content negotiation ultimately didn't play as big a part of the web as RFC 7231's text suggests the authors thought it would.
There's a lot of response codes squeezed on both sides by the fact that 1. they're too underspecified to be really useful (yes, it's great that you can return 402 payment required, but where is the browser supposed to go from there?) and 2. had they been specified enough to use at the time they were specified, they would have been utterly wrong. I don't think there's any way to square that circle at a standards level.
Have a read down the entire standard [1] with an eye to that. There's a number of codes that are useless (some deprecated), and a number of other codes that I feel uncomfortable calling useless, but compared to how the web evolved, certainly aren't working the way the initial designers intended. 406 "Not Acceptable", for instance, is for when the client sent up Accept-* headers that don't match anything the server offers. That's technically usable, but content negotiation ultimately didn't play as big a part of the web as RFC 7231's text suggests the authors thought it would.
There's a lot of response codes squeezed on both sides by the fact that 1. they're too underspecified to be really useful (yes, it's great that you can return 402 payment required, but where is the browser supposed to go from there?) and 2. had they been specified enough to use at the time they were specified, they would have been utterly wrong. I don't think there's any way to square that circle at a standards level.
[1]: https://tools.ietf.org/html/rfc7231#section-6.2