I know that what's going on on a typical website these days requires an enormous amount of computational power, but I mean, come on. That shouldn't be the explanation, it's part of the problem.
On a typical website all of the analytics are causing page bloat.
Sometimes there are frameworks like bootstrap but hypothetically those should be cached.
If you are looking at a web application then it has a framework that is a magnitude higher and the rest of it you see a significant increase.
It also has a lot to do with the fact that the Pinephone CPU is underpowered compared to anything from 2020 (or almost anything from 2015, really).
It's only slowed down by storage access speeds mostly.
https://www.youtube.com/watch?v=LdKNugT-mTQ
And this demo is purposefully using both displays at once to stress the device more. With single display mode there's less demands on RAM, and more bandwidth is available to CPU.
However, I would question whether uBlock Origin degrades performance – my own experience running Firefox on low-memory platforms like netbooks and the Raspberry Pi suggests that is not the case. Yes, addons use some amount of RAM, but if they prevent the device from loading a modern advertising-based webpage where the ads and analytics run into the many megabytes and the useless Javascript is CPU-intensive, it seems to work out as a net benefit.
For example, compare Twitter or Facebook to their recent SPA rewrites in React. I can't use either without sacrificing GBs of residential memory. Loading anything on those sites now requires many more CPU cycles than they did before.
A Webbrowser these days is simply much, much more than a static document viewer, despite this might be, what you want it to be.
And those who really want only simple HTMl rendering, I believe there are lightweight alternatives (?).
And if not, well then maybe there is simply not enough demand, because most people apparently want to be able to have a email client in the browser and do online banking, or edit Wikipedia articles in a rich html editor, or play games, or watch videos and share and comment them or even do video editing, ... all in the browser.
IMO they largely just want to do all these things in an open core VM, without risking installing malware on the ridiculously insecure proprietary OS most of them use if/when they use desktop computers.
No, then it is not.
Or do you mean in academical sense of functionaliy per byte? How useful is that?
And no, the firmware and drivers are sadly not memory optimized (or barely run at all), as ar as I know.