Seems to me too that at a very basic level we can pin a lot of the problem of Buddhism and Stoicism to their "physics" views that there is essentially a soul that survives death to experience new things in some type of future existence. That's at bottom of what they use to justify renouncing pleasure while it is available in this life, and even to consider that it might have been better not to have been born. In the absence of some reward for ascetic behavior somewhere down the road, why would any sane person ever choose it? (And for the present conversation we can just refer to the "sane" rather than worrying about the insane.)
With Epicurean physics and Epicurean canonics you can't even entertain such a suggestion as reasonable to consider, so you steer clear of ideas that what will happen after death justifies counter-intuitive decisions in this life.
At the same time, Epicurus does recognize that for at least most of us today is not the last day of life, so we do in fact make short-term decisions to choose pain for the sake of pleasure that comes afterwards.
But when you know that the playing field is exclusively *this* life, you keep that calculation in check, and come to reasonable conclusions in balancing the present and the future.