A strong argument or rebuke is powerful. It changes peoples' minds and gives a good argument and framing that is hard to refute. It takes the reasons for vaccine mandates away from those peddling them.

While those peddling the mandates and currently have power, can and might still use force to vaccinate people, their legitimacy is eroded by the rebuke and is seen as unreasonable. Using power in this way makes it quickly slip from your grasp.

So, it is not mere political theater. It is a check on the use of mandate powers.