I get that part but what tangible benefits will I/humanity see from it? Or is it more of a case of gaining more knowledge about how the Universe works in the hope that that knowledge combined with other knowledge may lead to something eventually?

This is how all science has always worked. Peasants were probably upset once that nobleman would spend their money on playing with mould in glass containers(what good could possibly come out of it????), rather than buy them food or clothing, yet that's how penicillin(and countless other drugs) came about. Do you think every inventor in history had a crystal clear idea what they were inventing and how was it going to change the world? Think about this as our R&D department - it has to get some money to keep pushing us forward.

And not everything is done as a benefit/loss game - I would personally invest significant time and money into finding out how the universe came about, even if such knowledge doesn't do anything for starving children in Nigeria. However, the beauty of it is that you on the other hand can go and spend YOUR time and YOUR money on whatever YOU please. As for public spending - if you don't like it, go and vote.

Space exploration is not for you. Your tax share of this mission, depending on where you live, is either zero or nearly zero. Asking for personal benefits from a space probe is silly.

However, your children, and their children, and so on will likely see benefits from it. The future is impossible to predict, however, so nobody can say what they will be. The principal benefit of missions like this is the new knowledge they generate. That knowledge is then the intellectual heritage of humanity for eternity, and can be used for any number of inventions, benefits, and future discoveries.

You are thinking too small. Even if somehow nothing ever comes of this mission, this is the sort of thing that humanity does not because it has survival value, but because it gives value to survival.