Billions of people are spiritual, but not religious. It's not like a "fake" thing. In fact, the Abrahamic religions have been fairly unique in their claim to universal dogma (i.e. orthodoxy) since at least Second Temple Judaism. The Jews of the Hellenistic and Roman periods were seen as peculiar for their rigid monotheism, practices demanded of the entire community, and hostile internal sectarianism.
Many of us in Western societies, dominated by Abrahamic monotheistic thought, don't see that there are other paradigms of being religious or spiritual that have served other cultures for millenia.
I'm not disagreeing with anything in your comment, but I did want to stress that @jononomo's comment was about being "religious but not spiritual" and yours was largely about being "spiritual but not religious".
As you point out, being "spiritual but not religious" is a pretty common thing and has been for thousands of years.
But I think this is the first time I've heard someone flip that phrase around to pithily describe an approach/perspective/whatever that I've noticed being mentioned more and more over the past ~5 years: that some structures, community, moral frameworks, practices, etc. frequently associated with organized religion have intrinsic value even when separated from the spiritual justifications/motivations that usually underpin them in those organized religions.
Taking things a step further: To use an example from your comment, @jononomo could be (I'm not claiming they are) saying that the concept of "practices demanded of the entire community" (something you named as something the "religious" Jews did that was peculiar to the "spiritual but not religious" Romans) is something that could benefit modern communities - maybe by bringing them together, helping coordinate collective action problems, whatever. And the justification for this would NOT be a spiritual reason, but rather for the very corporeal reason of improving human communities (ergo, "religious but not spiritual", if you like).
Many of us in Western societies, dominated by Abrahamic monotheistic thought, don't see that there are other paradigms of being religious or spiritual that have served other cultures for millenia.