Node and Electron and crew would agree.
A "modern" chat client (Element, Signal, etc) will lag on a quad core 1.5GHz system in terms of "typing into the text input box" (RasPi4, yes, I've set the governor to performance), when a single core 66MHz 486 could manage that trick without any lag in a range of chat clients. Hexchat still works fine, at least.
What we need to do is stop letting developers use high end, modern systems, and put them on something a decade old for daily use. Then maybe they'll stop writing crap that only works well on a 1-2 year old Xeon workstation. Google, I'm looking at you. Buy all your devs a Pi4 and make them use it once a week for a day.
High resolution displays for example impose an exponential cost right out of the gate. Just printing "hello world" requires more pixels as a function of the square of the increase in resolution. That's more memory, more memory bus traffic, larger bitmaps, scalable vector graphics formats that take more processing power to draw, antialiasing, ...
Again I am not writing off bloat. We could probably shrink most software by at least 2X and most Electron stuff by 3-4X. I doubt we could shrink it 10-100X though without sacrificing some of the things I listed up there, especially all the eye candy and rich interaction media.
I don't think pixel density has increased as much as you seem to think it has in the 1x scaling space.
I ran some very nice 1600x1200 21" monitors back in the day - ~95 ppi.
A 27", 2560x1440 monitor (my preferred native size) is 108 ppi.
The 24", 1920x1200, is 94 ppi.
I understand the issues with scaling a display, but those are more OS level, and shouldn't impact key-to-screen delays noticeably. It certainly doesn't on more recent Apple hardware, even if you're using some screwball non-integer scaling.
But the reality remains, I now have 6GHz of CPU cores, 8GB of RAM, and things are objectively slower than 66MHz with 24MB. That's not progress.
A less cynical take would shift towards the perspective of Gustafson's law. Modern systems attend to more stuff and have more capabilities and affordancies than older trimmer but also simpler software.
On Jevon's paradox, a countervailing force is ephemeralization or dematerialization, of which a large aspect is pushing away from resource intensive builds to more energy and information processing intense arrangements.
Those two aren't the only thing those groups optimizes for, but they are two of the main things. Which is why we have software bloat, neither group cares that much about user experience.
Given this as long as your software is efficient “enough” - which is easier to reach as computers get more powerful, you are better off optimizing for developer productivity on the desktop.
Now this dynamic is complete different on mobile and server since efficiency directly translates to battery use (mobile) and electricity and hardware costs (server).
Or rather, there’s always more work to be done.