Yes you're right, we know that DNA is inert and used as a storage device by an organism.

What we don't know is how an organism with no intelligence (cell), could develop code (DNA), archive it, rehydrate it and then parse and copy it like someone with intelligence.

Without getting too deep into it, it's just not convincing anymore to appeal to vast amounts of time and random chance to do something which is fundamentally within the realms of engineering.

Sure we do. It's littered with history, fragments from all over. And organisms today are more complex than organisms of the past, some of which still have remnants existing. So many stages of development as examples. There's no magic to it.

You're entitled to your opinion, but what you're suggesting is wrong. What you've said are some observations made and some interpretations based on evidence gathered but none of it concludes that cellular organisms invented DNA, that suggestion is still stuck in a chicken vs egg scenario.

The fact is, we don't know how these systems could have created themselves or been created abiogenesis. There are wildly different theories, but it's far from a closed case.

I used to think the same thing as you because that's all I was taught to think, but perhaps if you looked at what synthetic chemists think about abiogenesis you may find it interesting / informative to see what they have to say about the challenges involved in it. An interview with a synthetic organic chemist on the topic: youtube.com/watch?v=r4sP1E1Jd_Y