I recently noticed how many verbs have "directions" as adverbs:
"look up", "find out", "talk down", "figure out", "walk up", "look down", "point out", "clean up", and so on.
"Talk down" and "look down upon", could be interpreted literally, as one would consider the other person to be inferior, implying you would need to literally talk/look downward.
I was able to find some attempts to explain this use of "up" pointing out that one other possible meaning of the word is to "make it visible" or "make it appear", so looking something up would mean to make the desired information appear by looking for it. However, there was not much progress in figuring out the origin of this use, only that it dates as far back as the 17th Century and possibly a holdover from Proto-Germanic.
For "out", I could find little to no information at all.
This question is roughly on the same topic, although more specific, but the answers only mention this to be a common occurrence. I understand the existence of phrasal verbs, what I would like to know is more on "why" and "how".
Do we know how this came to be a "trend"?