Compatibilism often depends on epistemology, as it accounts for the nature of explanations that posit causes. The question is which level of explanation is relevant to explaining human behaviour, physics or folk psychology. There’s a pragmatic aspect of explanation that supports compatibilism.

Another factor is whether the so-called necessity in nature’s nomic relations is a hangover from deism, as David Hume’s problem of induction implied. The framing of the determinism vs freewill problem might be archaic if we assume it’s about the “ghost in the machine,” or a soul operating in a mechanistic universe.

Libertarian freewill would be miraculous, but that’s not the kind of freewill compatibilists have in mind. Limited, natural freewill would be a matter of autonomy or self-control, based on the human brain’s ability to define and affect itself by controlling its environment (via cultural symbols, artifacts, and so on).