more, less, and a story of typical Unix fossilization
In a sane world, Unix vendors would have either replaced their version of more with the clearly superior less or at least updated their version of more to the 4.3 BSD version. Maybe less wouldn't have replaced more immediately, but certainly over say the next five years, when it kept on being better and most people kept preferring it when they had a choice. This would have been Unix evolving to pick a better alternative. In this world, basically neither happened. Unix fossilized around more; no one was willing to outright replace more and even updating it to the 4.3 BSD version was a slow thing (which of course drove more and more people to less). Eventually the Single Unix Specification came along and standardized more with more features than it originally had but still with a subset of less's features (which had kept growing).This entire history has led to a series of vaguely absurd outcomes on various modern Unixes.