It also might be a result of the pattern matching proposal having only been introduced this year, and concurrency/coroutines having been a focus in C++20 alread

It also might be a result of the pattern matching proposal having only been introduced this year, and concurrency/coroutines having been a focus in C++20 already. Whereas compile-time programming has been discussed for a while now and is getting more well-baked, but still hasn't made it fully into the language yet and many (myself included) are eager to use it. See the revision history of P0707 for example.