There are no legitimate scientists studying the purpose of the Big Bang or the purpose of life.
That's probably because there is no "purpose" on display anywhere.
Let's take "evolution" for instance. Many on this forum may believe that humans are more "advanced" evolutionarily than bacteria. But that's kind of wrong thinking. In fact BOTH are EQUALLY advanced per evolution. Evolution is a passive filter which eliminates maladaptive features. The bacteria inhabiting its niche is as perfected as it needs to be to survive. It is the pinacle of evolution. Humans inhabiting their niche are as evolutionarily perfect as they need to be.
Evolution doesn't have a "direction", it just acts as a passive gate that keeps maladaptive features of living things from getting past so long as they happen before reproduction can happen.
Final causes (teleology) has generally been rejected by science because the modern scientific view is that the cosmos doesn't ultimately have a purpose, direction, or goal....at least not one amenable to scientific inquiry.
Again, what "final cause" are you referring to? I bet it differs from every single other human being's suggestion of the "final cause". That's probably because it is mostly just humans imagining something deeper. They look at a tree and think it's so amazing that it MUST have some deeper attributes, there must be a REASON nature created a tree. But that is little more than magical thinking.
I assume you are amply familiar with Ockham's Razor. So why propose an added complexity to nature when there isn't really any NEED for it? Just because one can
imagine some "teleology" for the tree doesn't mean it has a necessary existence. And it is possible to explain everything about the tree without reliance on any metaphysical features.
Philosophically-minded scientists have been discussing for a century what quantum mechanics really means, what it tells about reality.
Just because QM is difficult to understand from a macro-existence perspective and is truly and honestly weird as anything
does not mean there is some deeper meaning to existence. All it means is that existence is potentially weirder than we thought at the atomic level but it doesn't necessarily mean there is some "deeper cause" or "meaning" to anything.
QM seems to undermine determinism.
If something undermines determinism and things become truly random, then it would seem to indicate that even nature is trying to tell you there is no "plan". It just is.