The cortex is doing a lot of things.
Classic HTM focuses on both the temporal aspect and the sparsifying behavior of the spatial pooler.
TBT starts to move on (baby steps) to a system view. At this level we start to see the pattern completion behavior of the cortex. The cortex takes the noise buzzing/blooming world in and pattern-completes that to a region/map wide sparse representation of a prior learned pattern.
At some point the H of HTM will come into focus that then we will start to see the more interesting things that the cortex does - associating a pattern in one map/region to patterns in other maps/regions. This chaining of a perception in one map to remembered solution (guided by needs from the subcortex) is where the magic happens. If this interests you see my numerous posts on the “loop of consciousness” for the kind of processing done at this level. See the example below.
This is the level I have been looking at for many years - the system level behavior that does all the interesting things that the brain does.
Knowing what a single transistor does, even if in great detail, does not really explain how a collection of transistors in a computer draws a cat picture from the internet. Even stepping up a level to making gates and flip-flops is still a long way from kitten pictures. You need higher-level concepts and thinking to understand the system level behaviors.