Reading this article reminds me of all the advice in university on the importance of soft skills. The OP sounds like a competent technical worker but lacked the soft skills to secure his position.

All organizations have a consensus that guides it's decision. While heavily skewed towards leadership, even the consensus of the lowest hierarchy worker is important.

From what I saw in TFA, OP correctly identified that there was a need for FinOps but did not do the work to get buy in from the organisation. Even though I find it absolutely tedious and sickening. Some amount of politicking is inevitable for survival.