The Perfect Companion
Yes, the female companions of the Moffat era are smart, strong, capable, multi-talented, capable, prone to saving the day, etc.
But this is just the job of the companion. Even the worst of the classic series companions – Victoria, Dodo, etc – gets to be smart, strong, capable, etc when required. They don’t tend to save the day in the classic series, but they always do what is needed and expected of them. It’s a tautology: the companions do the companion things more or less successfully. That’s not something that’s entirely untroubling, but – for good or ill – it’s how this works. In the revived series, a great deal more is expected of the companions. It’s actually worrying just how much is expected of Martha. But the point is that they all step up because that’s what they’re in the text to do. The ones that don’t, fail to be companions (i.e. Adam).
You also have to look at what they do and what happens to them on top of their basic role as companion. Rose rejects the roles of shop worker, daughter, girlfriend, etc. in favour of gradually becoming a committed social actor. Sadly, she is reabsorbed into such roles by the end (a major disappointment). Martha throws herself into the role of social actor to a huge extent, ultimately rejecting the Doctor because he cannot satisfy her level of newly self-created level of self-esteem. Donna escapes her emotionally unsatisfying family life and work life to, once again, become a social actor. The theft of this from her is horrific, and is clearly meant to be. It all goes wrong by the end of the RTD era, with them all married off, etc. But this, however awful (and it is crushingly awful), is still a relatively late development.
The early-to-mid Moffat-era companions, by contrast, are given the arrangement of their domestic lives as their main extra-curricular activity (so to speak) on top of their ‘duties’ as a companion, right the way through.
Amy’s character – i.e. what she does, says and thinks on top of all the fulfilment of ‘companion duties’ – is focused upon getting married or not getting married, being a mother or not being a mother, having a domestic home life or not having a domestic home life, being a wife, saving her marriage, etc, etc etc. The Doctor actually intervenes, several times, to ensure that her personal life runs along the proper lines. Whereas, in the RTD era, the Doctor was a force that (selfishly) drew the women out of the confines of personal and work life and into the wider arena of social action, in the Moffat era the Doctor actively tries to provide Amy with a perfect, middle-class domestic idyll. House. Car. Marriage. Etc.
River is ostensibly an archaeologist, or sometimes an assassin, but her character arc (if the random string of things she does can be called a character arc) is all about her assimilation into stability via her romance with, and marriage to, the Doctor. …