Quakerism would fit the bill, though I don't know how many people are choosing it these days.

This is hard to define as there is ambiguity between religion and spirituality.

Even a subscription to pure scientific worldview is a religion in itself.

QAnon?

QAnon seems to have many parallels with "prophetic" religions where you don't have a priesthood class organizing specific groups of followers e.g. parishes, but you have a priesthood class interpreting the words of a prophet and popularizing these interpretations; in this case "priesthood" isn't a formal distinction, but de facto you tend to have specific minority of people fulfilling this role.