> Nobody can ever know an ultimate why, for obvious and well established philosophical reasons

Yes we can, you are just presupposing that philosophy is ultimately ineffective. For example Hegel gave a presuppositionless development of all metaphysics among other things. It’s not some kind of philosophical consensus that ultimate justification is impossible

Philosophy can be perfectly effective as a tool of thought while still being unable to resolve self evidently unsolvable “ultimate questions”

Interesting word soup. Ultimately, no, you cannot build a valid representation of the universe from nothing and you need observation and validation. You can presupposition whatever you want when you are talking about unproveable models, but it says more about you than the universe. Until we have a reason to think that there is a "why", discussing what it is is completely unnecessary and futile because 1) it does not change anything about our understanding or the predictions we can make, and 2) it is not something we can observe, measure or prove.