Today, this question came to my mind when I started cerebrating about what it actually is.
My conclusion is that: Te-form is simply another name for the concept of 連用形+て(助詞) that native Japanese speakers would use or they were being taught this way, right?
And in accordance with that, the te-form usage should be roughly equal to or a part of て-usage, Could this line of thinking get through or it's just nonsense?