Well it's hard to quantify the relative importance of personality and cultural fit vs intelligence and programming ability. You can turn what you said around, and say that you can be the nicest, coolest person in the world, but if you are a fucking moron who can't code, you won't be very useful.
But the big tech companies seem to have settled on the current process, and are therefore probably fairly happy with the people their interview process is giving them. As to looking at previous projects, that makes sense but it might be more time consuming to properly evaluate someone like that.
The big tech companies haven't been happy with the people the interview process have been giving them – all we heard about for a long time is about how they couldn't find anyone to hire. Perhaps this settling you speak to marks the end of developer shortages in the industry?
Not really. These are two separate issues. If I am a gold panner, I might be very satisfied with my gold panning technique, and yet complain that there is a shortage of gold in the river.
But the big tech companies seem to have settled on the current process, and are therefore probably fairly happy with the people their interview process is giving them. As to looking at previous projects, that makes sense but it might be more time consuming to properly evaluate someone like that.