There are none anymore. We now know that throwing a bunch of bits into the linear algebra meat grinder gets you endless high quality art and decent linguistic functionality. The architecture of these systems takes maybe a week to deeply understand, or maybe a month for a beginner. That's really it. Everything else is obsolete or no longer applicable unless you're interested in theoretical research on alternatives to…
I've been doing it since early 2019 and there are still subtleties that catch me off guard. Get back to me when you're not surprised that you can get rid of biases from many layers without harming training.
I broadly agree with you, but the timeline was just a little too aggressive. By about 10x. :)