Now, let's be fair, here: the comic shown here was created in 1966. Sue being on the team AT ALL was an accomplishment, for that point in time. Lee and Kirby did have her as the damsel-in-distress a lot, early on...but as time passed, they got better. Compare Sue's work here with, for example, any female character on Star Trek's first season, for example. Taken in context, Sue is generally pretty liberated, considering she starts the comic as a Jackie Kennedy clone and is being filtered through a comic written primarily for young boys. You also have to keep in mind that Lee's goal here was 'Heroes with Hangups', as he described the FF: Johnny the hothead with an inferiority complex, Ben the self-hating grump, Reed the cold intellectual with a guilty conscience and Sue, the girlfriend/wife who feels unappreciated. Keep in mind that Reed and Sue have only been married for a few months at the point this comic came out...and already a chronically distracted Reed is taking her for granted AGAIN.
As for Byrne's run: I think you're pulling one piece out of a distinguished run and coloring the whole thing with a broad brush. Byrne changed her from the Invisible Girl to the Invisible WOMAN, ramped up her abilities and made her a much more complex character. Sue became not just a mom, not just a wife or force to be reckoned with, as well as a capable leader in her own right.
I agree that Sue has benefited from time...but that's as much to society's changing views of women and the diversification of comic book audiences as anything else. I can't really think of many female characters in 1966 who were that more advanced than Sue. Hell, Batgirl was introduced solely as a way to show that Robin wasn't gay...and she was eliminated in 1964 (except on TV, where she was getting tied up a lot). I mean Carol Danvers around this time was Captain Marvel's love interest, like most female characters. And we don't even need to discuss what Lois Lane was like around this time.