The biggest thing is the spectacle of the flowers themselves, and the reflection on time passing for humans given by such a long time span between when the palm is planted and when this spectacle can be observed.

There's also the spectacle of seeing so many once in 40-80 years blooms happen at once - which the article doesn't touch on, but is an awe-inspiring look into how regular biology can be, despite us thinking of it as messy and random. You'd tend to think that over such a long timespan, the trees would get "de-synchronized". Of course, that wouldn't make sense evolutionarily - they almost certainly need to all bloom at once to have a good chance of reproduction. But getting a biological process to happen 80 years from now on the same day/week for dozens(?) of trees across a park is a marvel in itself.

And that's across a park. Let me tell you about gregarious flowering of certain bamboo species, which are synchronised all over the world. They bloom at the same time. Nature is a deeply commited eccentric :)

https://en.wikipedia.org/wiki/Bamboo_blossom