In the current example

std::pair<int, std::string_view> pairs[] = {{2, "foo"}, {1, "bar"}, {0, "baz"}};
std::ranges::sort(pairs, std::ranges::less{}, [](auto const& p) { return p.first; });

the result of sorting is same of that using default std::identity.
It might make more sense to use [](auto const& p) { return p.second; } as the projection.

Moreover, std::format("{}", pairs) (after sorting) gives [(0, "baz"), (1, "bar"), (2, "foo")] or [(1, "bar"), (0, "baz"), (2, "foo")] since C++23. Should we change the result in the example to match std::format?