So you actually just recently missed a truly excellent post about very much this topic!

Here is the link to the thread: https://www.reddit.com/r/AskHistorians/comments/5hx9mf/why_did_the_north_american_bison_never_take_off/

Along with this other longer post from /u/snapshot52 https://www.reddit.com/r/AskHistorians/comments/4j42ag/there_was_military_involvement_by_the_united/d33w2sx/

Simply put compared to cattle for consumption Buffalo left much to be desired as a domesticated animal. While on the other side of utilization, for their fur and pelts, there was simply no organization really concerned about or invested in protecting them. While organizations from the US Army on down saw their eradication as a method for advancing civilization forward, and would be key in restricting the freedom of movement for the Plains Tribes.