A stage performance is an entirely different situation, and there I agree PA may be necessary where the venue dictates. This includes morris perfomances to a large audience in a large venue, when PA may be entirely appropriate. However in a small venue performers should be able to manage without PA.

Using PA for morris in the street or pub car park should be entirely unnecessary. Ironically it seems this is brought about by the fashion for ever-larger bands, which then feel the need to mic up in order to bring up the quieter instruments.   Morris sides used to manage very well with just a single fiddle, concertina or melodeon, so I question the need for it in most situations. It is then compounded at massed morris events, as sides don't want their own music to be drowned out. It is a retrograde and to me unwelcome development.