Facts. The 9900K its better at games by a small margin because games have been made mainly to favour Intel since Ryzen was not really a "gamers" CPU. However when you check benchmarks that test the CPU as a whole like C20 even the 3700X trades blows with the 9900K, let alone the 3900X which is in a league of its own.
Many game engines have Intel specific machine code optimizations in areas where performance tricks are needed - there is a bit of a twist to that though in that often similar ways of tuning for AMD CPUs simply don't exist. A lot of the performance optimizations patches for Zen are to make up for software issues such as the Windows scheduler not working optimally for the CPU.
i doubt we will ever see that day intel will pull ahead at some time again whilst amd are putting up a massive fight atm and i think they will for a few years but they have to find a successor to zen one day and intel have more money more man power and can aford to take more risks with having such a market share on the prebuilt and laptop etc which makes them the most money amd really havent cracked that yet
It'll come if/when Intel feel sufficiently threatened the bigger problem than tech development is management (or rather lack of) and for some reason a hang up on 10nm - even though they are in a position to bypass it now they seem intent on throwing good money after bad.