No such thing as a tree? So you mean all those binary trees I've been inverting have been a lie? My whole world is shattered.

Indeed, it simply is not a phylogenetic categorization but a physio-ecological one. Tree, like shrub, liana, herbaceous, woody/non-woody are all terms solely used to place plants into functional groups based on how they grow. None of these has to do with their taxonomy.

So the question is, what is a tree and is having secondary growth necessary to be one? Because monocots, like palms are, don't have secondary growth, they use some workarounds. But why should that matter in the definition of a tree? I don't know. So yeah, a coconut palm should be considered a tree. But it hasn't got to do with phylogenetics (like explained in the article you linked).

Also, millennia ago there have been vast forests of lycopods!! Just imagine huge trees that are actually spikemosses. So why shouldn't a palm not be a tree?

Of plants native to the Canary Islands, wood independently evolved at least 38 times!

You forgot about the myth of vegetables.

Except that yes there is. It's just not a scientific term. Same with fish.

https://blogs.ifas.ufl.edu/duvalco/2024/01/23/are-palm-trees-really-trees/

Halt! I'm here to check the expiry date of your facts!

Neat read, thanks