Is Boost still something people reach for in newer projects? Anecdotally most adoption I've seen happened in the 00s and very early 2010s (pre everyone mandating C++0x/C++11), I only rarely see it around these days.
edit: boost.org is a blast from the past, still looks exactly like I remember it from like 2008. Down to the "Get Boost" shopped on an emergency off button!
AFAICT Boost.Asio is still the go-to networking library. (Though Asio is also available as a standalone outside of Boost, I didn't know that until recently.)
Apart from that, Boost has quite a few goodies such as Boost.Json, Boost.Program_options, Boost.Interprocess, Boost.Lockfree, Boost.Unordered, Boost.Dynamic_Bitset, etc.
Some libraries, like Boost.Atomic, Boost.Thread, Boost.Chrono and Boost.Filesystem, simply became obsolete with modern C++ versions. In fact, they served as the blueprint for the corresponding C++ standard libraries.
Personally, I have been wary of using Boost in the past because it's such huge library, but CMake integration is actually quite good these days and I found it pretty easy to use. Documentation is also quite good IMO.
edit: boost.org is a blast from the past, still looks exactly like I remember it from like 2008. Down to the "Get Boost" shopped on an emergency off button!