Thing is, it really changes the equation of whether it's worth or not.

If you or some other senior engineer knows X, then perhaps they can implement X in an hour and things remain simple.

If your team does not know X, then it will take a week to learn X, understand it, try it out on a toy project and implement it in production (which alone might make it an overkill, because it's not worth a week) and it becomes quite plausible that we'll implement it wrong in a way that will bite us later.

So unless the benefit is huge, then it's quite reasonable to say "x is overkill" for your team simply because you don't know X.