That's a feature of physics, not vague notions around what "we" have built. Time is and can never be "plentiful" nor "shared in". Everybody has a limited amount

That's a feature of physics, not vague notions around what "we" have built. Time is and can never be "plentiful" nor "shared in". Everybody has a limited amount of time which is theirs and theirs alone, and what you do with it matters - it's called opportunity cost. When you spend a large amount of time on something, it's not unreasonable to consider whether it was worth it (although that worth can reasonably be measured along other axes than money).