It's not "dead", what kind of crappy binary take is this. It absolutely still work to an extent where making an attacker lose time does slow down attacks, thus increasing security.

You can absolutely make an agent lose its mind thus making it spend more tokens, to an extent where it might not be viable, but in all case, slowing down or making something more expensive is a direct way to increase security, so wasting either token or human time both is useful.

SBO+Real security > Security.