Special snowflake option.
Limited distance: I think the distance limitations on darkvision and other special vision types is bad in 5e, but the problem is with the way 5e handles distances, not distance limitations on special vision types. Measuring distances in feet works fine on a grid but is difficult to utilize without one. But if a hypothetical 6e took the 13A approach and did abstract distance bands, I don’t think limiting the ranges of special vision types would be bad.
Binary Darkvision: I think binary darkvision was a good design choice in theory, but in practice it’s not really binary, is it? You’ve got 60 ft. Darkvision, and 120 ft. Darkvision from race, and dark-to-bright Darkvision from the Devil’s Sight Warlock Invocation, and functional low-light vision from the Skulker Feat. So, in theory I think binary darkvision would be a good design choice, but since 5e doesn’t actually have binary Darkvision anyway, I think it’s a poor use of the game’s design space not to utilize the various Darkvision mechanics more.
Lack of Dark-to-bright: As noted above, 5e does actually have a dark-to-bright vision mechanic, it’s just that it only comes from one optional feature of one class. I don’t think the decision to have or not have dark-to-bright vision is inherently good or bad design though. Again, since 5e has it, I think it is poor use of design space not to have utilized it more. But whether to include it or not include it is a neutral choice, what matters is how it’s used.