Of course on the whole understanding makes our lives better, but if you're asserting this for everything, it's probably some kind of a survival bias. The understandings that aren't really useful are often forgotten, while the useful ones are passed down through generations.
It's actually very easy to get caught in understanding niche topics that genuinely find very little application.
In my experience, something about the mind makes it think it is able to know the correct answer to these questions, which is a remarkable but little studied phenomenon.
Do you mean this literally, as in this is knowledge (JTB) that you possess?
> Pursuit of meaning of life is completely different topic
Is this a part of reality, or of something else?
> no need to try to mix those two
How does one go about accurately determining what is needed?
Understanding of reality via physics gave us all electronics too, including one I use to write this and one you use to read it. That's a noble goal on its own, no need to meddle with that.
Pursuit of meaning of life is completely different topic, for different folks, no need to try to mix those two. Plus its very subjective - tons of folks already found it or simply don't care about it.