Reshade

Reshade works for gameplay as well, depends on how many effects you are using, the more effects you are using, the more demanding it becomes for your PC. Some effects like depth of field doesn't work at all for gameplay because you will not be able to see what you are doing so I have them bound to a shortcut key on my keyboard so I can easily turn depth of field on or off. Same goes with some bloom and lighting effects because they will make the menus impossible to read, most presets have shortcuts so you can turn those off, otherwise you have to turn them off yourself in the settings which is pretty easy to do.

You didn't mention your computer's specifications. It's highly recommended to have a dedicated graphics card. GTX 950 , newer equivalent Nvidia or AMD card would do depending on the desired settings. ReShade acts as an overlay meaning it sits on top of the UI + game. Use the tools built-in hotkey for screenshots or another program like Fraps to capture screenshots.

You might be surprised not all of us use it. ReShade has gotten more optimized and stable over time. In my experience, you can still experience drops in framerate even with an overkill PC. We're talking 5-10 frames or more/less depending on certain circumstances. It bugs me enough to just use Photoshop instead. Others are not so bothered by it so it just depends on what settings you're using, PC hardware, and if you even care to track FPS like I do.

I have Reshade, but really the only thing I really turn on is the sharpening filter, because I just like a bit more crisp.

Now that I've used reshade for a few months, there is no way I would go back to not using it. Sometimes I toggle it off and on just to oggle what a massive improvement it is! I only use about 6 settings, and there is a plethora to choose from. Some are just sort of extreme filters and not really practical unless you're trying to do some real artsy photos, I suppose.