You are playing at a low resolution. Numerous benchmarks show that Ryzen outpaces the 2600k+3750k at higher resolutions and also at higher graphics settings. The newer intel chips still beat Ryzen at single core performance (say, the 7700k), but the vast majority of games released in the last 5 years use 3+ cores.
I'm currently running a 3750k. It's a great chip. It's done well for the last 4.5 years and will continue to do well as an HTPC. However, I bought a 1700 because I game at 1440p and in VR (I don't use VR much but I love it and will surely buy the next version, which will almost certainly have a higher resolution). It's also a risky move OC'ing such an old chip. I'm running the 3750k at 4.2ghz on air without a problem. Pushing it further, or increasing the voltage, is too risky.
Not to mention all the little benefits that come with owning a modern chipset: NVMe, USB 3.1, etc. If you plan on playing at 1080p then there is no reason to upgrade. This makes a lot of sense on a projector. Gaming on a 1080p monitor (especially if it's a TN panel) doesn't make much sense in 2017.