I am a photographer, photography accounts for all of my income and this is my stance so far:
If your work is individual, consistent, reliable and most of all, of the standard associated with that of a professional, then the chances of you actually agreeing to provide a service for the folk with budgets under your standard rates are slim. Your not going to provide a full days coverage for £250 so either someone will or the couple goes with what's available (relatives and guests efforts).
The chances would also be as equally non existent with you providing a service to the folk who may ask for it for free, so again, that particular couple aren't getting any of your work are they and again, either someone will step in or the couple goes with what's available (relatives and guests efforts).
I find this more than accurate:
It's our job to keep our socks pulled up
If your truly happy with what you do, if your truly satisfied with what you can achieve, then whatever the technology, you should really have nothing to fear.
To be fair, budding wedding togs offering to do a wedding for free is of no threat to the industry in my opinion.
My concerns are whether it's a threat to this forum. I remain undecided.