Interesting, it kinda feels like the opposite is true for me, at least on mobile. In 4 years, I've gone from a 1.4GHz A53 SD425 to a 2.2GHz A78 SD695 SoC, a 6x increase in single thread performance in 4 years for me. I also during that time got a powerful laptop with a Ryzen 9 5900HX CPU.

Meanwhile, it's still not unusual to see my Internet speeds drop below 1Mbps, often hovering around 100Kbps-300Kbps, on data or crappy university WiFi, which sometimes has a ping of no joke, 20000+ on my laptop when running Ubuntu. I can sometimes reach high throughput of up to 100Mbps, but when I don't, my Internet speeds often chug.