First and foremost, this is the technology community. If you wanted to see mature tech that is in production, you're in the wrong place.
Second, battery tech has had steady improvement for decades. The cell phone I had 30 years ago had a battery pack that was about as big as my current cell phone with a capacity of 500 mAh. My current cell phone has a battery tucked away somewhere inside it that has a capacity of 4000 mAh. The price per mAh has also gone down about 99% over that time span. There have also been three major "new battery" types over those 3 decades. The changes have been happening whether on not you bothered to notice it.
Fossil fuels are currently the largest disconnected power storage by overall power used. You know, the thing cars use when they aren't EVs. You may have heard of diesel and gasoline generators, or oil-fueled ships.
As per the previous part of my comment that you quoted, my point was that incremental changes can accumulate to the point where at some point revolutionary changes can occur. We increased capacity and longevity by a factor of 10 over 30 years, have a new technology hitting mainstream, and another that could double power density in the next 5 to 10. Yet you seem skeptical that's possible, in spite of the decades of advances we already have made.