Many countries seem to be moving towards recommending face masks, not just those in Asia.
The UK government says there's no scientific evidence. However presumably you could set a really high bar on what constitutes evidence (rather than work with sensible extrapolation of what we do know) to avoid telling the public that they'd be better to be wearing masks at this time when their inability to provide PPE to medical and caring staff is well known?
I'm not clear masks prevent you catching covid 19 but it they prevent the other person transmitting it then that's virtually the same thing and masks - were these available - should only cost pennies.