In Rema OC 203:2 one of the reasons given why we don't make Ha'etz on berries is because its shoots die during the winter and a new set of shoots and buds grow out from its roots during the summer, thus it is not considered a tree.
והני כיון דכלה עציו לגמרי בחורף והדר פרח משרשיו מברכים עליו בורא פרי האדמה
This is mostly based on a Geonic responsa and also partly based on the gemara in Brachos 40a.
But I'm having a hard time figuring out exactly what the geonim mean. It was clearly known to the Rishonim that berry shrubs and plants are not monocarpic (See tosfos ibid.), so when the geonim say that berries are Ha'adama because they die during the winter they clearly do not mean to say that the whole plant (besides for the roots) dies. Rather a more likely explanation is that the old shoots die (or lose their vigor) during the winter, and in the spring a new set of shoots grow on the old shoots which flower buds that eventually bears new fruit. The problem is that apple, pear, plum and all Ha'etz trees work the exact same way! The old shoots grow new shoots and spurs every year or two which flower buds that produce the new fruit.
So in short what I'm asking is, how do the berry plants and the fruit trees differ in the way they fruit (According to the understanding of the geonim), and why did they consider the berry plants "dead" in the winter, more so than a regular fruit tree? As far as my knowledge extends they both grow new shoots and spurs on the old shoots that so called "die" during the winter, and on these new shoots they sprout new buds in the spring. Berry plants are not monocarpic and they dont die after their first crop (contrary to what some believe), they usually live between 4-6 years producing many harvests over its lifetime. So why do we make on berries Ha'adama unlike apples and plums according to the geonim and the Rema?