Do robes help or hinder Anglican mission? Previously I argued that robes are not required by Christ's mission in which we share. They are beneficial rather than necessary for the mission of God.
A basic point about robing is that it is a form of uniform, with the uniform being influenced by robing through the previous centuries rather than, say, by negotiating with a uniform making factory and offering a cheap, hardwearing form of overalls with appropriate logos on the back.
What I think we are seeing, at least in Western cultures, is that Anglicans are finding two ways to be in mission in respect of people encounters where the question to robe or not arise.
One way is through providing familiar forms of worship which fit with expectations within our cultures about how the church should be and about where God might be encountered. Hence robed clergy, choirs, etc, leading traditional forms of liturgy (by which I mean, using words agreed by common synodical decision). Even in a post-Christian world, there are plenty of images of the church provided by TV and movies, most of which involve some pastiche of traditional Christianity in which the Vicar (English scenes) or the priest (American scenes) are robed up in order to lead a wedding (of hero and heroine) or a funeral (of some Mobster crook!). I say "pastiche" because the words used seem to be a mix of Catholic, Anglican and scriptwriters made up wording!
Another way is through providing forms of worship less familiar from TV screens and more familiar for those brought up in churches geared to informal worship. There may be some use of agreed liturgical wording, but the general approach is for the leader to lead spontaneously, using, for instances, rapport rather than responses to make connection between front of house and audience in pews or, more likely, individual seats. In this form of worship, which is quite widespread across the Western Anglican world, wearing robes is out of sorts with this informal genre.
I like to wear a suit and will happily wear one to certain kinds of meals (a formal dinner etc). But I am a fish out of water if I wear a suit to a friend's barbecue. Such an informal meal is best suited (bad pun, I know) to jeans and t-shirt.
But, if you agree with me, that both styles of worship have their place in an Anglican church which has a missional outlook - which seeks to be accessible for people searching for God via attendance at a worship service - we have a small rubrical problem, at least here in NZ.
For nowhere in our prayer books do we find any words which effectively say "Dress for the occasion." We just talk about what robes to wear.