Some may object to my saying mortals can never be free from all pain and say something like What's the use of Epicurus' philosophy then.
At least as to me I don't object to it, and I think most everyone here (where we generally have a realistic view of things) will agree. Total absence of pain is pretty obviously a theoretical goal more rather than established fact for any human being at any time. And it's confusion about that which is causing most of the debate and division on what Epicurus was talking about. (And that's most likely why you're concerned that "some may object to [your] saying that" because we can all observe that most of the world is talking as if Epicurus were in fact describing some real condition of total separation from pain.)
Last night in our zoom, Tau Phi offered the analogy that it is understandable that we are always feeling something because we are made up of atoms moving through the void, and the atoms never stop moving, and our sensations as emergent properties of these motions is going to naturally be always responding to internal and external motions so long as we are together and alive.
Similarly, I would expect there is another "physics" analogy on why we should not look to "ecstasy" as the best definition of the highest pleasure.
We talked last night about the "impossibility" of constant ecstasy, and I think we can also analogize that to physics terms. At least theoretically, the "gods" might be able to remain in constant ecstacy, if they so choose, because it's a characteristic of the intermundia (from Lucretius) that it supplies their every need and it is a totally friendly and supportive environment.
Our world, however, is not so constantly supportive. We're constantly buffeted by external and internal motions that would tear us apart literally and figuratively if we did not act to respond to them. A constant state of ecstasy in response to outside influences would not provide a mechanism for us to repair and sustain ourselves in the face of this buffeting. We can't constantly eat fish and drink wine and have sex because given the nature of our world that will lead to dissolution from any number of factors. We *must* take time away from being stimulated so as to exert our own actions to keep us as nearly as possible in constant pleasure, keeping in mind that there are many kinds of pleasures and that some are more productive of repair and regrowth than are others.
While we all recognize the benefits of ecstasy, we also have to keep in mind that we need to pursue other pleasures, and even at times pains, so as to keep our own atoms of body and mind in healthy condition and peak performance.