You don't quite understand the concept of a light cone.

Yes, we get new data all the time, and the extent of our horizon is growing. But it is always finite. You cannot look backwards past the big bang singularity, and you cannot look forwards beyond "now" for any value of "now".

No, you fail to understand a light cones end at finite points. If I travel 1 light year, then I observe a different light cone and it takes 1 year for somone that stayed behind to receive information from me. This effectively means you can see something before the light cone at your current location would observe it.

If you consider a light cone as all points out to infinity then that’s the entire universe. Instead at each point in time you have a different light cone that extends to the age of the universe.

In theory we can never see past a second limit based on the expansion of the universe, but that’s yet to be observed speculation without any consistent theory of what’s going on.

We can’t

But 200 years ago we “didn’t need” relativity and then we did

Asking questions and wondering about the things we don’t know is how we now know about many valuable things that, in the past, didn’t appear to be valuable

You may want to temper your claims with "based on the currently accepted Standard Model" or "with high probability." Because paradigm shifts occur.

See my OP: https://news.ycombinator.com/item?id=18094991

"Barring some major unforeseen revolution in our understanding of physics..."