The bottleneck is the whole pc. But that's all in your head. It's a low-end Ryzen build that's only going to get mediocre output.
The R5 1400 gets similar performance to an i3 8100
You have a rx460.
Performance
This graphics card was designed and marketed towards the competitive MOBO gamers. A light weight, small form factor GPU solution that offers mobility, so that gamers travelling to events can bring a smaller cheaper gaming rig. The Radeon RX 460 2GB can play most modern games at medium graphics selection on a 1600x900p screen res and expect around 45+FPS
And no OC. You can research online how to OC a Ryzen, it's not difficult, plenty of documentation out there from forums to YouTube. Ryzens get performance boosts from using fast ram (2800 is on the slower side of fast) which helps them think faster since Infinity fabric is based on ram speeds.
It's a low-end, low-performance build, in layman's terms its a Dodge Mini-van, and yet you seem to expect it to be a race car. Sorry, not going to happen.