What’s the purpose of the difficulty bomb after the merge?

I thought the difficulty bomb was there to force miners to stop mining progressively, and after the merge there would be some sort of hybrid POS-POW system.

But now I’m reading that after the merge, September 15 aprox., all validations will be POS, and the difficulty bomb will start exploding only 2 days before aprox., but the bomb is very progressive, and it would not have any noticeable effect.

So at this moment I’m wondering, what’s the purpose right now of the bomb? Did it have one but now with all the delays it has none?