Earlier quoted context omitted.
Software expands to fill the available resources. If you want more efficient software, build it on less powerful hardware. AI training runs are no exception!
That's not what "software engineers" in Silicon Valley or Redmond typically do. They write software that usurps other people's computing resources, e.g., CPU, storage and an internet connection that they do not pay for. It's one reason I use NetBSD, custom barebones Linux. I write and compile software on single core old computers and cheap eMMC laptops.
There is a lot of fun to be had working with vintage hardware in spare time though