Well I mean if I wanted to be extra pedantic, I would argue that we've been in that phase since LLMs were first introduced.

Before that, we had 0. After that, we had more than 1.

A leap as far as that is hard to recreate.

But that wasn't my point. That's just trolling.

The actual point is that LLMs aren't gaining new capabilities anymore. They just get more reliable at the ones they already have; turning what was a coin flip to some higher probability.

That's (intuitively speaking, not strictly mathematically speaking) kinda the mathematical definition of diminishing returns.