I think we must have been very lucky and arrived at a quiet time of day / the year or else it just didn't used to be as busy but I remember going when our kids were very small (10-15+ years ago) and it was a lovely quiet trek and we walked right in to see the waterfall at the end.
It is a scary path when you have a toddler, especially if they are a bit tired and determined that they don't want to hold anyone's hand - it makes me nervous because I imagine I'd easily fit through the gaps if I tripped and fell !
It's still a great hike, just worth getting there early or picking a quieter time of the season to visit.
I wonder if the bike-race that day which meant more people at the campsite were 'captive' due to the road closures led to it being busier than normal?