The flop count is misleading. Even though Cell was a beast in crunching numbers and general power terms at the time (even today its no slouch), utilizing that complicated architecture in games was very difficult and was almost 100% never going to be fully utilized anywhere near what its theoretical max was.
Only certain parts of the CPU could actually utilize most of its full potential(the SPU's), and on top of that, third party devs and even first party devs had to also actively sacrifice CPU power to prop up the weak GPU in the PS3 to keep par with the 360's stronger GPU, because the Cell could also do a lot of GPU graphics rendering as well.
The 360's CPU, the Xenon, was much more standardized and nowhere near as ambitious as PS3's CELL design, but it was much easier to get results out of and use, and as a result most 360 third party games ran better on that machine(in addition to the RAM design and stronger GPU of course)
The Jaguar in PS4 and XB1 follows that principle as well. Its FAR easier to use than Cell ever was, and so, in combination with the general architectural efficiency of a CPU made in 2013, you actually get far better results CPU wise in gaming on Jaguar than you would during Cell's applications.
When people talk about CPU power in the 8th gen, nothing should be contrasted with CELL, as that was a weird situation on its own. Instead, the contrast should be with Xenon, as that is far more comparable. Its already been theoretically benchmarked by a dev on Trials Fusion over on Beyond3D, and apparently an 8 core jaguar clocked at 1.6GHZ is around 2.5 to 3x as fast as Xenon is in general gaming usage.
Considering both XB1 and PS4 use 7 cores at this point for gaming, they are getting pretty close to that level.