This contrasts with say, a subsistance farmer who produces food for their family and lives in a small community where every product of their labor has a known and appreciable impact. In that case, the equivalent goal of "changing the world" is "helping the community", which is much more attainable.
I get joy from figuring out how to solve a tricky UX issue, or from finally discovering the root cause of a difficult bug.
The work itself can be fulfilling, regardless of any potential deeper meaning.
My experience is that the same job also has a large range for meaningfulness depending on how well leadership manages to facilitate it.
That's a reason why the quality of most Japanese products is superlative. Another nation that is passionate about their stuff are Italians, but they value good looks above all. The US values profits and growth and China values high output volumes.
At least where I am from, Italians have a reputation for shoddy products, laziness, and not caring. As you say: They are happy as long as the facade looks good. Behind the scenes is a mess.
You bring up Japan yet they're known for being excessively and pointlessly overworked to the point of depression and suicide. It is a culture that rewards obedience and prostration to your job above everything else. So many were peer pressured into finding meaning in their work to such an excessive extent, and of course didn't become happy because its a system that optimizes for cohesion and stability, not happiness and meaning.
I'm absolutely guilty of this. I'm a software engineer, and I feel proud of having worked on products that millions of people use. Steve Jobs's challenge to "put a dent in the universe" is axiomatic for many of us.
Yet I know that in other countries (e.g., Japan) there is a belief that any job, no matter how humble, is worth doing well and that passion for excellence is a virtue inside us and is not conditional on the perceived pecking order of the job.
If we had such an attitude, maybe it would be easier to feel fulfilled--if you're holding out for changing the world before you can be happy, you're (statistically) going to die miserable. On the other hand, maybe a culture in which we give 110% to meaningless jobs is just another chain for the rich and powerful to keep us productive.
I honestly don't know.