I'm with you, thinking about architecture is generally still a big part of my mental effort. But for me most architectural problems are solve in short periods of thought and a lot of iteration. Maybe its an skill issue, but not now nor in the pre-LLM era I've been able to pre-solve all the architecture with pure thinking.

That said architectural problems have been also been less difficult, just for the simple fact that research and prototyping has become faster and cheaper.

I agree, that's another factor. Definitely the mechanical act of coding specially if your are good at it gives the type of joy that I can imagine an artisan or craftsman having when doing his work.