Reflections alone would be one of the most impactful additions. And in contrast to most others: very difficult to do otherwise. I'm a bit surprised by the sudden push after long phase where it seemed like they would never come.

Contacts: yes please. Variadic indexing is one of those things everyone writes their own helper for. But this standard facility is very welcome indeed.

Some additions seem a bit of of scope for the standard of a language that famously refuses to fix mistakes. So in weary about std::hive, networking, physical units.

And an underrated cherry is at the end: cleaning up those "ill formed, no diagnostic required" clauses in the standard. For those who don't know: there are things forbidden in the standard which the compiler is allowed to not tell you (because it's difficult for the compiler to prove it). In particular this is omnipresent in the constexpr world. Leading to silly redundant code that manually assets things to explicitly trigger the compiler to check for errors.