How hilarious, This is a clue, closing volume, always varies, always, always, always. It has varied for the last 30+ years and beyond, that eye can remember. Volume , on rare occasion's can be used and not on the close. This thread is cluttered with your giant charts. As if we don't get enough screen time, really.
Volume can be quite deceptive. I wouldn't personally argue against sophisticated studies of volume as it would be hypocritical of me to argue against something I haven't seen in action, yet I must add if strike rate is average than I fail to see the benefit of its primary dependency or implementation as a secondary tool.
Is gas in a car tank useless? Volume is activity. Volume is $$. Therefore it shows where money is being put. While it can't be completely trusted ..because of brokers...data feeds...dark pools..etc it can be useful in showing the larger footprints of institutional money. In the end some volume is shown and it is generally good enough to be useful. The real first problem is most traders do not know how to interpret it. The second problem is it can complicate trading on a small TF and cause one to miss a good trade trying to correlate price and volume.