Not all software is getting slower faster than hardware is getting faster.
It has always been possible to write slow software.
And the important point is: it _is_ annoying, an actual bootup in 5 seconds is easily possible from a technical perspective, and would much improve the user experience.
Take systemd, I remember it brought a lot of startup time improvements for a while, or at least promised them. I don't follow Linux very much these days, but when I do a standard installation of a popular distro - sloooow startup. Last I looked I had an issue with tons of virtual serial devices created serially, took probably 10 seconds alone.
Parkinson's law at work.
But to your actual point, of course you can write software that runs not slower, or even runs much faster, than the software of 30 years ago that ran on machines of the time. The exception proves the rule (while I feel it's always been so obvious that there was never a proof needed).
This slowness costs users so many hairs pulled out. Programmers who think that "this is acceptable" lack the awareness that they haven't even tested the software under only slightly unusual conditions which is when everything is already crawling to a halt.
When that "bundle" is 1000MB while technically there is no reason it should be more than ~1MB, many operations that you might want to do as a developer / trying-outer of the bundle take 1000x longer (no shit). Not unlikely, in some cases that even applies to runtime performance.
Why in the world would you accept that when it takes only a little discipline to get it down to a "reasonable" overhead of say, 10x???