Job specs

Have been to a few interviews lately and one thing stands out :

When shown what is used day in day out by the team in question,some technologies used are not highlighted or even mentioned in job specs or by the recruiters… why is that the case?

Can totally understand it if the tech in question is dated, so leaving that out of the job spec while attempting to get potential applicants for the role might stand more of a chance of not putting them off in case they think it’s a company using dated technology.

But to leave what’s used daily out of a job spec seems like a sneaky thing to do.. why do recruiting teams do that? Why not just state clearly what tech is being used daily by the current team and try to get the right people with the right skills in?

Understand too that some teams are transitioning to “move forward” with tech they’re using so by emphasizing new tech rather than what’s used in reality for the bulk of work involved in a specific role , they are hoping to attract a new set of people with the new skills to future proof their teams.

Despite that, it is still almost like recruiting based on a lie, is it not?