Ask HN: How accurate is browser benchmark Speedometer 2.0?

I remember seeing an article here not too long ago, it's about the new Speedometer 2.0's release and for testing browser speed. I was curious so I tested on my early-2015 13" MBP along with my month old new PC (Ryzen 1600 stock + 16gb DDR4 2400mhz + NVMe SSD).

The scores are from using the benchmark with all extensions disabled with latest updates http://browserbench.org/Speedometer2.0/

On MAC, Safari 67, Chrome 67, Firefox 47 On PC, Chrome 76, Firefox 64, Edge 46

Should the scores be higher if the hardware is better? I saw on some forums people are getting a score of more than 100 with older generation hardwares. I thought my new PC would get noticeably higher score due to newer parts, or am I missing something here?

Regardless of speed, I'm pretty browser agnostic, switched to Firefox due to the looks but I use all the browsers depending on tasks on hand. Asking mostly due to curiosity, would appreciate if anyone can shed some light.