The article is much less optimist than you seem to be interpreting it. It's basically "is there a hard cap on the age you'll die, or is it just random and independent of age past a certain point".

It says nothing about the aging process. Being older than 90 still sucks for the most part, and this article says nothing about quality of life.

It also is a very minor point, in a practical sense: is it impossible to live past 120, or is it possible with then odds of 1:10^9?

Suppose you are an immortal working on some long term goal, some plan that will take a few hundred years to complete. It is a complicated plan and you will need to keep it all in your mind, along with its history as it progresses, in order to guide it to success.

If you try to lead an active life throughout all this, perhaps your brain will acquire too much irrelevant information, interfering with your ability to carry out your plan.

So you sleep for decades at a time, just waking up long enough to check on the plan, learn about changes to the world since your lest check, and make adjustments. Then back to sleep.

Consensus created not by people with experience de facto. At least not the majority.

This just indicates a failure of imagination on the part of the author.

Even if we perfect the art of 3d printing new body parts and using gene-targetted cancer treatment, that may not make you spry, less forgetful, or less wrinkly