Interesting

If you actually read the page instead of stopping at the line you thought agreed with you then you'd have seen that the same page says that banana plants are only considered trees in its "broadest sense" based on "common parlance." Meaning people often call them trees because they look like trees even though they're not actually trees. So in the the most generalized non-technical use of the word they could be considered a tree in the same way a child's drawing of a brown scribble with a bigger green scribble on top can be called a tree. Fun fact, did you know that koala bears aren't actually bears? Honey badgers aren't actually badgers. Bearcats are neither bears, nor cats. Killer whales aren't whales. Electric eels aren't eels. Velvet ants aren't ants. Things get named based on appearance all the time, but that doesn't mean they are the same thing as what they look like and are named after. That's why those names and terms are referred to as common/vernacular/colloquial. And lower on the same page your quote is from it says:

A commonly applied narrower definition is that a tree has a woody trunk formed by secondary growth, meaning that the trunk thickens each year by growing outwards, in addition to the primary upwards growth from the growing tip.[4][7] Under such a definition, herbaceous plants such as palms, bananas and papayas are not considered trees regardless of their height, growth form or stem girth.

You wanna know who they cited for that definition? Actual botanists. Wanna know what their citations on the broader definition had to say about banana plants? That they are herbaceous plants, and are only called trees because they have a "tree-like" appearance. Even the ones debating the definition of tree clarify that botanically bananas aren't true trees. I can follow up with that if you want but that'll be a long comment if I'm gonna go over the sources and their contents, because some of them are heftier than others.

When they say "trees aren't well defined even in botany" they don't mean "banana plants can be considered trees in some botanical definitions". Botanically, banana plants are not trees. The debate in botany is based on stuff like whether trees have a primary trunk, or rings, or if they have to be a singular entity, etc. That complicates the definition of tree in reference to shrubs vs trees, or clonal organisms like pando vs singular trees, sure, but bananas are not in question on that front. They don't even have an actual stem above ground most of the time, what we think of as the stem is just a bunch of leaves wrapped up together. Hence why it's called a pseudostem.

I named several Wikipedia pages, including 2 focused specifically on banana plants and their genus, which say that the banana plant is not a tree botanically. I can even list more Wikipedia pages that specify the difference between trees and herbaceous plants in a way that wouldn't include banana plants if you want. But you found a couple of lines on one page, talking about the broadest non-botanical use of the term, and you're clinging to that one like gospel. So apparently you don't actually view Wikipedia as The Right Resource™ unless it's a specific line that agrees with you.