Sure but my point is more general: if I create a new lean web-like protocol and client and it can't display videos, feature interactive content, arbitrary styles etc... How do I drive adoption?
I can convince the suckless folks that "less is more" and that it's "the unix way" but outside of that circle I'm not sure who's going to use my software.
All software seems to be going in the opposite direction. For instance I'm a heavy user of IRC, these days the type of communities you could find on QuakeNet 15 years ago are on Discord, a super heavy webchat client that manages to slow down my beefy desktop computer when run on pre-quantom Firefox. The Discord client is probably several times heavier on resource usage than the Quake game itself!
It might come from a piece of software that solves a problem for some group of people that a browser can't, and then evolving towards the mainstream replacing the role that browsers have right now making them obsolete
It depends. You could say the same to Igor Sysoev when he started to write Nginx, for example.
So, e.g. web browser with all the main Chrome or Firefox functions but working 2x faster on mobile and eating 3x less memory would disrupt the browser market indeed.
The gaming industry still has room for lone coders to make a difference. Many of the top indi games are/were written by individuals (KSP, Minecraft) or by very small groups (Factorio). Sometimes being able to do something leaner, with less code, means you can win ground against the biggest of big guys (City Skylines over SimCity).