Let’s leave the networking aspect aside for a moment.
When a language is compiled, the source files go through a pipeline of parser -> preprocessor -> compiler -> assembler -> linker, to end up with an executable. With interpreted languages, the source code is instantly executed line by line by an interpreter software. With JIT languages, the program gets compiled and optimized into portable bytecode, which is run by the language’s runtime.
If I had to guess, web pages (i.e. HTML/CSS/JS) are most likely run by an interpreter that is a web browser, but isn’t that inefficient given that most of what people do on computers is browsing the web? What about browsers, what standard is there that specifies how each language should be run/rendered? What pipeline does a webpage go through to end up as a process in a computer?
This is why it’s vitally important to use FIrefox rather than any Chromium-based browser (even ostensibly “degoogled” ones), BTW: we need a robust diversity of browser engines to prevent Google from having hegemony over web standards.
TBH 2-3 would be good, since each browser takes a monumental amount of effort/money to optimize and maintain.
Like, my best case somewhat plausible scenario would be Apple (and maybe some other vested interests?) merging Firefox and Safari into one open source effort that can keep up with Google (with Safari being a “branded” Firefox). There just isn’t enough money for a couple of open efforts to keep up with Chromium.