There is a recent thread on this topic on another forum where I posted the response below.
In my case, it is not so much about oxidation with bare wire connection to speaker binding posts. It’s the tightness of bare wire connection that isn’t good in comparison to banana plugs. Over time, the connection with bare wires will become loose, resulting in a poor sound quality.
I recall my system sounding considerably off at one point of time. I checked all cabling to see if the power cords are touching the interconnects and speaker cables. I also checked the rack to see if anything was amiss. I later found the culprit to the poor sound - the connection at the speaker terminals was loose as I could turn the nut to complete one full circle before it’s tight again. Yes, a full 360 degrees circle which is crazy. After the nuts were tightened at all binding posts, it’s all glory again.
After that incident, all my speaker cables come terminated with spades or bananas. Banana plugs are my favourite. The connection with terminated speaker cables will not become loose with time. It’s tight and secure. It is also much easier and convenient to use terminated wires than bare wires, and they look better too. Lastly, all good speaker cables come factory terminated.