There is also a heavy obligation upon the leadership of the shul not to drag out the Tefilah such that majority of the full Tzibur finds it very difficult to focus on the davening for such a long period of time.
Remember, Tzibur (community) includes those spiritually energized and those not spiritually turned on.
The 368 “maneh” measures of the Ketores (incense burnt in the Temple) include the 9 highly energized cinnamon and the 70 measures of much less spiritually energized galbanum.
When I was in Kol Torah 1973-4, my Rebbe was known for very long Shemonah Esrai. But when he had to lead the davening later that year, his silent Shemonah Esrai’s were much shorter, to avoid burdening the Tzibur.