in our own very limited experience, every effect has a cause, that in turn has a cause, and so on, but our experience is limited. there could be (logically, there must be) some initial cause or causes that are not effects. but naming any of them doesn't really solve anything to those who insist every effect must have a cause, it would just shift the question to what caused that just-named initial cause. whereas once we accept the premise that there are initial causes that aren't effects, what would the point be of making the cause-effect chain any longer than it needs to be to explain what we observe?