It is not, actually. Barely sufficient for a lot of modern games at 60Hz and cripplingly bad if trying to target 120/144Hz.
The IPC difference between Piledriver and Ryzen is over 40%, and there is another 5% (roughly) between that and Skylake / Intel 14NM IPC, clock speed is only a useful metric when comparing chips in the same architecture, but clockspeed * IPC gives a rough idea of how fast they actually are, before worrying about latency and other oddities.
TL;DR a 4.8Ghz Piledriver CPU is about as fast as a 3.2Ghz Skylake or Ryzen.
As a comparison, a lot of newer games require a 4.8-5.2Ghz Kaby/Coffee Lake (Skylake with minor tweaks) to reach 120 fps with any GPU. Some games simply cant due to being too limited by single-core speed.
Definitely better for rendering than gaming - in fact that is the only reason anyone well-informed in hardware ever bought one, in an age where other 8-core simply did not exist remotely close to the same price.
Totally fine for LoL and other e-sports at 60Hz, which is the vast majority of gaming, though.
Current games are rapidly shifting towards 6 threads (or even 8/12/16 for a few), due to how popular the R5 1600 was last year and the release of Coffee Lake. And as CPU speeds have not increased meaningfully for over 5 years, while games continue to get more complex and use higher polycounts (animation/physics load), CPU and RAM threads/speed are becoming more and more important; "only GPU matters for games" was true 10 years ago (and for 10 year old games), but not anymore.