The counter argument to the “argument from ignorance” is given enough time for observation and better scientific tools, everything can be “knowable”. I don’t think we can ever arrive there. Once we figure out the origins of the Big Bang do you think the questions will stop? At the end I think it becomes an existential question: is everything an accident or is there purpose/meaning inherent in the universe? For purely practical reasons I am finding that building on purpose rather than accident or “we don’t know yet” or “it’s just the way it is” leads to a more fulfilling experience of life. Is this a sort of psychological sedative? Perhaps, but again, from a practical sense, it has improved all areas of my life without a noticeable side effect.