I would only note that for the vast majority of my experience these streams can only return up to a single match. Determinism isn't really preserved by findFirst, either, unless the sort order is set up that way.

Finding the first Jim Jones in a table is no more reliable that finding any Jim Jones. But finding PersonId 13579 is deterministic whether you findFirst or findAny.

Perhaps you work in a different domain where your experience is different.