> "You actually don't need all that crap to serve adverts, or really even to do tracking: people managed without it in the 90s. It's just that it's more work to get the same effect without a buttload of JS in this day and age"

While I sympathize with this sentiment, this is also the entire history of computing in a nutshell. Moore's Law has driven us orders of magnitude beyond where we were when personal computers first came into existence; but Wirth's law[1] has kept pace. The laptop I'm typing this on right now has 8 GB of RAM, and that's already become pathetically tiny, pretty much the minimum viable for a consumer PC; I have to keep checking my memory usage or I'll spill over into swap (on a mechanical drive) and have to wait several minutes while my computer recovers.

Performance in computer applications fundamentally doesn't improve. Stuff gets prettier, sure, and applications do more. But things will still run about as slowly as they always have, sometimes a little worse. (There are exceptions - some things like loading programs from tape, or loading things from an HDD once SSDs were invented, were so painfully slow compared to their replacement that you'd have to actively try to write slow code to get anywhere near that performance.) It's ease of programming, flexibility, and freedom of design (in aesthetics and interface) that the advance of computing technology has always enabled. And all of those are extremely valuable in their own way, and can make applications genuinely better - even allowing qualitatively new things to come into existence that wouldn't have been feasible before - even if they don't run faster or take up less of your memory.

(To understand why, think about the development of - say - computer games since the 90s. For all that we mock poorly optimized games, how inaccessible would game development be if we required them to be coded as efficiently as Carmack built Doom? For all that mindlessly chasing "better graphics" has ballooned costs and led developers to compromise on gameplay, how many games simply couldn't be translated to 90s-era graphics without fatally compromising the experience? How many projects would never have been started if we set the skill floor for devs so high that a hobbyist couldn't just download Unity and start writing "shitty" code?)

(Or think about something like Python. Python is a perfect example of something that allows devs to massively sacrifice performance just to make programming less work. If we kept our once-higher-by-necessity standards for efficient usage of resources, something like Python's sluggish runtime would be laughable. But I think you, and I, and everyone else can agree that Python is a very good thing.)

[1] "What Intel giveth, Microsoft taketh away."