My point was that Atlas/Delta have had a lot of time to get their bugs found and fixed, while the F9 has had 20 launches overall. It seems reasonable to me to expect that the reliability of F9 will rise with time as more bugs are found and fixed. So if you wanted to launch something today, you would reasonably consider this record to be a reflection of current risk. But I don't think it makes sense to extrapolate and say this will remain constant in the future.

But then again, I am partial.

The SpaceX design should be dramatically suprior to the aging Atlas and Delta designs because they are designed to be cheaper to build in the first place and they will be game changing if they manage to land the first stage and immediately turn it around for multiple launches.

Atlas and Delta are certainly good platforms for high reliability but they are expensive and they aren't making much effort to bring the costs down. Bringing the costs down would require design revisions that might undo that 50 years of design stability.

If SpaceX or someone else comes up with a reliable design at a dramatically lower price point ULA wont be able to sell their launchers unless its to a money is no object customer like the U.S. military.

Recovery and rapid turnaround of the first stage could make space access cheap enough many things would become possible and affordable that are not currently, due to high launch costs, like expeditions to Mars or large space structures.