I didn't arise right away, and was thinking of some theses on meter before standing up in the morning.
1) It is universal. Caveat... It could be true that there is some language out there without meter. I am just saying it is "universal enough., e,g. widespread enough to be something significant. The exception does not prove the rule; it is just an exception. Subthesis: prosody does not require a system of writing. It is preliterate.
2) Speech prosody is also universal. Every spoken language will have a prosody, that is, a way in which it is spoken with regard to intonation, accentuation, etc...
3) There will be a relation between linguistic prosody and poetic prosody. Poetic prosody uses features of speech prosody as its basis. This relation is not always natural or straightforward. For example, Romans adopted Greek ideas of quantity; earlier Latin meter is accentual. However, let's say that there is a relation. It is hard to imagine an English prosody without accent. Counting syllables might work for a particular poet, and that's fine, but that won't form the basis of a widespread practice. Don't tell me to write haiku in English by counting syllables, because the Japanese haiku doesn't use syllables as its basis, but rather morae. You will say, well that's a pedantic distinction, and I will say pedantry is my middle name. In other words, saying that Japanese count syllables is ignoring the relation in the language between linguistic prosody and poetic prosody.
4) There will be some constraint, the idea of something that cannot be done in a particular meter, or something that has to be done. The meter is artificial, in the sense that not every utterance that follows the speech prosody is metrical. The meter can also stretch or compact the words to make them fit. So "suave" is two syllables (in Spanish) but it can be "su - a - ve" in some metrical context. "Cae" is two syllables, but in Antonio Machado's poetry it often one. So, combining (3 )and (4), meter is natural but also artificial.
5) Musical prosody is the setting of words to music. There will be a relation between the meter of the music and the meter of the poetry. Once again, this relation might be a strained one. I'm just saying a natural tendency might be, for example, to sing accented syllables on the musical accents. In strophic poetry, with each stanza being in the same meter, you can sing each stanza to the same melody.
There are things that are super obvious, but yet spelling them out cogently is not always easy. For example, I am pretty certain that a small child can know the meter of
"you must never go down to the end of the town if you don't go down with me. " The child won't make a mistake in reciting this line. But an English professor might call it iambic pentameter.