After being dominated By all you Hotshot killers when I first came to the big boy servers, I thought the same thing, It has to be the device, as I was on a pretty crappy one at the time.
I then did what I do in life when bit by something like this Dogfight Bug, and promptly went out and spent thousands of dollars on top end equipment for all platforms (Windows 8/Android/Apple,ios).
Including A new Hotrod Computer with Big HD widescreen and programmable Joystick controller with the intentions of eventually hooking the HDMI out to My Sharp 70 inch Quattron HD TV, because I had thought the same thing to begin with.
The bigger the screen, the quicker I'll see them before they see Me.
The following information, along with a lot of other equipment information is what I have found to be true regarding a Big screen, and any advantage.
The Pixel Per Square inch capability of the higher end tablets exceeds that of the HD big screen TV's with the exception of the latest Ultra HD 4K televisions that are just hitting the market.
In addition depending on the PC you have, there is a limitation on the definition capability of not only the video card in the PC, but also the Definition limitations of the Application Software itself.
I find that there are slight differences in the effectiveness of each of the devices and they're software platforms, and how well My old crusty eyes can see that little dot of an enemy airplane in the distance, and the ability for Me to line My cross hairs and/or tracers up with that little dot.
And the computer/HD big screen combo is actually at a slight disadvantage in My opinion compared to something like the ipad for long range precision shooting, especially when considering the keyboard/joystick control to tablet/Phone accelerometer precision differences.
I'm not trying to sound like an expert, I could be wrong on some details, its just what I have found to be My opinion so far.
I do know one, or two decent precision shooters playing with PC, but ultimately I would have to agree with everyone else here, and say that your abilities for getting good with what device you have learned to use is going to be the main basis for your success.
I hope this helps and wasn't too long for all my buddies!

Arlen/Von Len