Maybe I am too optimistic for my own good lol, but I honestly just think they developed this as fast as they could when they saw the writing on the wall about Twitter. Threads IS Instagram, it was easier and faster to develop this way instead of starting from scratch. That’s why deleting one would delete the other.
Edit: I just wanted to clarify I am in no way defending Meta and I don’t even have an Instagram account. It’s just the way I see it but I admit I can be wrong about this. We’ll see what happens in the coming months/years.
OP made a mistake, they’re just going to wander endlessly in the hallways until sunrise.