No GPU is ever really 'too much'...
But....
It's more a matter of how much of the very good GPU's hypothetical performance at 1080P/1440P are you sacrificing by getting less than the 9900K...
Here are a few 1080P/1440P comparisons...( many of which make AMD fans quite angry, BTW!)...
View: https://www.youtube.com/watch?v=3rOVfeujof4&t=498s
Many folks seemed certain the difference between AMD and INtel is but 5-10%, and, when confronted with CPU comparisons using top GPUs show the difference can be 30+%, folks then complain ad nauseam that 'the settings were not high enough to shift the load mostly to the GPU', etc...
The R5-1600 gives 'good performance, but, it would be hard to deny that in some games at even 1440P, it might be down some 30%...; will this matter if getting 100 fps on a 60 Hz monitor? No. WIll it matter when trying to achieve 144 FPS minimums for a 144 Hz monitor? It sure might.
Pairing a 9900K with a GTX1050 seems odd, as would pairing an R3-1200 with an RTX2080Ti....; most rigs are well in between of either, with lesser degrees of 'oddness', and, all opinions are only that.