I know this isn’t climbing.

It’s a big deal to say best ever. It’s a summary of everything that happened so far, it’s calling the top. Implicit is that it means ‘best so far’, but if like Sergey Bubka, the Ukrainian pole vaulter, you are constantly probing the limits of your sport or of hyperbole, you will loose credibility if ‘best ever’ starts to sound a lot like ‘most recent’.