What's the deal with unshakable inner peace?

I keep hearing about this concept of reaching a state (through hardcore meditation or otherwise) where nothing can touch your tranquility, you are unaffected by external circumstances.
While inner peace is absolutely something I long for, this raises a lot of questions in me. I hope I don't come off too provocative, I'm not looking to argue, but I'd like to hear your thoughts on these (or just on the topic in general):

-Wouldn't being so detached and unaffected mean, that you are also unaffected by the positive things: the little joys of life, the childlike wonder about the world etc?

-While it's logical that removing all desires and attachments would also remove the problem of suffering (ie desires/attachments being unfulfilled), isn't it also like advising someone unhappy with their wallpapers to burn their house to the ground?

-If we take it to the extreme, wouldn't someone completely unaffected by external circumstances, completely free of desires and attachments, basically end up catatonic? And at that point... you're mentally checked out from this earth already, so why continue living? Even if it may be extremely rare to reach that stage, if that's the logical end goal, is it worth it to go in that direction?

-I get the appeal of seeking truth beyond the mundane and material, wanting to see behind it all, like behind a veil of illusion. But I also feel like there's truth inside it all, like in the unfiltered primal experience, "the human condition" or even "animal condition" (since we are animals at core?), in raw honesty of feeling what you feel. Or what do you think of this?