The best we can hope for I think is that open source will create frameworks/foundations on top of which people can then try to build. Elixir Phoenix has been that to some extent, basically taking the rails philosophy but making it super light and fast (my Phoenix APIs run with 40MiB of memory and response times ~1ms). Maybe those sorts of advancements can save us, but I can't think of a way to address the browser that way and realistically right now the browser is a huge area of the bloat. A ton of code that runs in the browser is terribly optimized, but even the base is quite big.
The real question is what happens first: change in software to adapt to slow growing compute or change in architecture to revitalize Moore's law.
This is a gross oversimplification. While there’re inefficiencies and process abuses, this doesn’t mean nobody cares about speed and resources. It might look that way to purists who’re focused only on tech part of the businesses.