This effectively means that - in the future you are going to want more cores too - another point for AMD in your specific use case.
Finally, you are writing in C++, not Java, python, or other distinctly interpreted languages - and this brings me to an area of some bias, so take the following with a few grains of salt.
C++ is getting more developers year on year, Java is actually dying, apple development (and with it their proprietary languages) is slowing down as their market satiation (and loss of Jobs) becomes painfully clear. (IPhoneX == Samsung Galaxy Edge == every other phone on the market).
This is mostly because of C++'s modernization, C is faster to write and safer than ever before - and honestly has better multi-platform support than virtually any-other language; meaning a better user-experience - but that isn’t the only reason.
C++ is fast, it’s compiled and optimized binary code is mind-mindbogglingly fast, I remember a talk given by Bjarn Stroustrup where he spoke about converting a scientific protein-folding tool from Python to C++, the result being the code ran in seconds rather than weeks - (P.s. I despise python). Because C++ does better, it uses less of that now-not-getting-faster single-core performance, and that means a better user-experience.
C++ is winning not because it’s easier for developers though - it’s not, if you want easy you would use any other language, C#, Java, etc. It’s winning because it provides the end-user a better experience.
And there in lies your biggest problem buying AMD - most users run Intel, if you can’t afford other machines to test your game - you will run into a wall.
A real-life example, I wrote code - code ran perfectly on my computer, on a shiny new Intel I7 - is slowed to an absolute crawl. Not because the I7 was worse, but because my development assumed 8 processing cores rather than 4.
So - in conclusion, I would personally buy AMD - but there’s a lot to consider!