I did all the thing I do now 15 years ago on my laptop. Sure video quality have improved, screen resolution have increased and I can do more stuff online, if I want to. All the daily stuff, browsing the web, hobby programming and paying my bills online, why can't I do that with 1 or 2GB of RAM?
We could do 100Mbit networking 15 years ago, or even 20 years ago, so the increased network speed shouldn't be an issue.
The network speed is by no means an issue. The problem is that all websites feel the need to mess with their DOM and execute megabytes of JavaScript just to do basic tasks. Then your bottleneck becomes the processor speed and the amount of RAM, the latter a larger obstacle in my experience.
I think your posts underlines an important fact: Nowadays more and more tasks require an up-to-date internet browser. These browsers need a lot of RAM. Both their complexity and the websites' is increasing all the time.