One thing that goes against this trend of decline is the last gasp of the sail merchantmen with ever increasing competition from steam, and smaller crews, making chanteys more necessary, but it's likely that by 1900 there weren't many tall ships left trying to compete.

By 'decline' I simply meant they had outlived their usefulness as you summarised.

As you say, John, we are left with a few contradictory accounts after the event, and what is likely, looking at the various factors involved.