Confidential funds are usually allocated for special purposes that can't be publicly disclosed that would otherwise compromise its purpose; a good example of this is if it's for national security (funding for intelligence agencies, counter-terrorism), emergency responses (disaster relief without bureaucratic delays), or undercover operations that could lead to massive arrests of high profile targets.
The keyword here is the lack of accountability and scrutiny to the public eye, hence why it's subject to use and abuse.
Unfortunately, it only means campaign funds for the next election for anyone using it in our government + pocket money and bail-out money in case things go south... at least that's my opinion.
government gets bag of money called "confidential fund" that they get from taxes
government can spend this confidential fund without anybody knowing about it (except themselves) on any "projects" that they deem need funding.
the re are no required receipt or invoice or even just a piece of paper to document what the funds were spent on.
we are really not supposed to know where this money gets spent on, because it is "confidential". government just tells us "just trust me bro. this money is being put to good use *wink*" (with skull emoji)