Even worse, "I would argue that..."

It's not hypothetical if you are here, in the current tense, arguing that. I've mostly cured myself of the habit, but its tough.

Also used incorrectly most of the time. They meant to use “debatably”.

Arguably:

- used to say that a statement is very possibly true even if it is not certain (merriam-webster)

- in a way that can be shown to be true (cambridge)

ie. you can be prove it through argument, not “you can make the argument”