In your original spectrum android view, I could only see maybe 2 or 3 neighboring networks on the same channel. But as you can see, your access point can see many more (and I would imagine its more if you expand the list). So there is a good deal of competition for channel 6 alone, no way of knowing for sure how much contention there is channel utilization wise.
The built in spectrum tool gives you an 'idea' but my experiences with it have been lack luster so I tend not to believe everything it shows me.
It's possible that with all the CCI your seeing, there simply isnt' much you can do to improve it, other than move to 5GHz.
However, I case this is the bug i'm referring to earlier with specifically the MR34 model and 2.4GHz throughput issues, I would say swap out the AP with a different model (or just place one on a desk nearby and test). Or contact support, have them downgrade to 24.12 and try again. That will confirm if its the environment, or firmware issue.