8Gb of ram is the bare minimum to run anything gaming in Win10 sufficiently. 16Gb is overkill for most things gaming in Win10. Unfortunately DDR4 comes in 4Gb sticks, so you could use 12Gb (3x4Gb) but would suffer enough loss of performance with 1 stick in single channel mode, that you'd generally get better results with just 2x4Gb in dual channel. A single 1x8Gb is about as bad a decision as it gets, either use 2x4Gb or 2x8Gb for maximum performance. The downside to just 8Gb is that at anytime there needs more than 7Gb of total system usage, Windows will virtual memory, meaning that it'll use the ssd/hdd as tempory ram. If you have no ssd, just a hdd, expect serious hiccups and stuttering since hdds are figuratively almost 10x slower than ram.
While pubg has low system reqs to get basic playability, to play it well requires the recommended settings. To play it really well requires better than recommended. With your system as is, expect medium settings at best to see solid 60fps at 1080p, but even then, minimum fps could be as low as @40fps.