In the big picture, I doubt much has changed, as big picture items rarely do.
Bob Cupp used to say that 8 gca's got 80% of the work, leaving the (then) 300 gca's to fight over the last 20%. Those 8 have changed out over time, as has always been the case, and the other fighters have probably reduced by over 100.
On the other hand, we see a lot of relatively new faces (some spreading out at the encouragement of their more famous bosses) who are getting more and better projects. I guess you would have to call them either regional, or maybe just young architects, like Brian Ross living in Texas but working in Tennessee. It's a cycle, and whenever the bigs get either too busy, too expensive, or too full of themselves, there is a niche in the marketplace that must be filled. That the US is a youth oriented culture helps those get started, at least IMHO.
I remember being that young guy! Fun times.
As to some of the other things discussed, like selling work, I see things as still the same, although as Ian mentioned, I believe the sales process has been mastered by more and more consultants. Instead of touting their past work, it seems more effective now to just present your vision for their course, and hope (or know through research) that it matches theirs. If I show any pictures of my past work now, it is always with a comment that basically says, "and this is just like your project because....." I find that 3D renderings of at least one proposed green are almost standard and necessary now. (One project told me they hired the other guy because their 3D renderings were better than my quickies.)
I recommend any gca trying to stay in biz read "Selling the Invisible." It explains why the big names have it so much easier in selling, i.e., the biggest thing a selection committee wants to avoid is making a mistake....and as the old saying went (needs to be updated) "no one ever got fired for hiring IBM.
Short version, I remember my Dad (A Campbell Soup salesman, so he had brand name going for him) uttering within a year of his retirement, "When does this get any easier?"
No, nothing has changed, LOL.