Technology

You're only thinking about the occupancy part of efficient use of available resources (and even then only partially) and forgetting all about the utility value part.

RAM used 100% of the time is not more efficiently used than RAM used 10% of the time if it's being used for activities that deliver much lower utility, something made even worse because using RAM consumes additional resources in the form of power hence running it isn't actually free and you if the utility of it's use is lower you might actually be destroying value by using that power for a much lower utility use than it could otherwise be used for.

That's the point others are making by pointing out that if that RAM is in data centers running AI 100% of the time it might actually be in use less efficiently than RAM used for multiple activities in people's computers at home where it's idle most of the time.

Yours is basically the same fallacy as the one about how people working more hours per day means they're producing more.

"More use" is not the same as "more value created" because time is far from the only factor in determining how much value is created.

PS: If you really dig down into the utility value for Mankind of most modern day computing you'll find that a large fraction if not most of it is basically entertainment, gambling or some for addition and thus doesn't produce actual economic value. For example, how exactly does social networking such as Facebook produce economic value for Mankind - it's basically a mix of entertainment and an addiction that directly creates or help create nothing, and instead it mainly wastes people's time. At best it could indirectly deliver value by improving worker efficiency in activities that actually create value because people were happier with Facebook than without it, but by all indication that's not even the case as it's creating epidemics of psychological and social problems especially amongst young people. Those things are extracting value rather than creating value, so the computer RAM running Facebook software is probably a net negative in value creation overall - it creates little or no value overall (it extracts value from some to others but doesn't actually create any) whilst consuming power to run, and all of those factors put together might mean that in overall value creation terms that RAM being idle or even in the refuse bin would actually be better than being used for Facebook software.