What I don't understand is why they remove the function row. In my opinion, the problem with size in keyboard design is merely width.
OK, I understand this argument. I recently got a new Matias Mini Tactile Pro, which is a 75% layout that includes all the F1-F12 keys, and it's nicely compact on my desk. Why get rid of those keys?
Let me turn that question around. . . Why keep them? What are they good for?
I've been primarily a Mac users for the last 20 years, more or less, and I can't remember ever finding any use for any of those keys in any application. Applications are generally controlled through drop-down menus with keyboard shortcuts, and they almost universally use Command and Alt key combinations for those shortcuts. The F-keys were so under-utilized that Apple turned them into media keys and also use F3 and F4 to activate Dashboard and Expose. They even made that the default setting and require us to hold down Fn to access the original F1-F12 functionality, because it's so rarely used! So, forget about moving F1-F12 to a layer. For Mac users it's already there.
IMHO the F-keys are relics from a time when there were no drop-down menus, and programs like Word Perfect and Lotus 1-2-3 used those keys for basic application control -- sometimes even coming with templates you could set on top of your keyboard to help remember which ones did what. That was a long time ago, and nothing works that way any more. From where I sit, that entire row of keys should be considered deprecated. Yes, let's be able to access them through a Fn layer just in case we accidentally stumble across some ancient, eccentric program that requires them, but otherwise we should be able to forget that they ever existed. It's either that or spend even more decades staring at that entire row of useless keys while struggling to dream up some way to make them good for something again.
Now, let's consider the F77 for a moment. It doesn't have any F-keys, but it does have a 15-key matrix pad that we can program for anything. You can put all of your nav keys onto that -- four arrow keys, page up, page down, home, end. That leaves seven keys that you can set up as media keys or what-have-you. The F-keys can be accessible as a layer on either the number row (the usual choice) or through the 15-key pad, assuming you ever stumble upon some program that actually uses them for anything. Seems like just about an ideal solution to me.