Okay, I'll try.
Why is bitcoin going to suck in all the stored value in the world? Because it's better money than fiat (or gold).
Why is it better money, well to explain that we need to answer the question, "what is money?". And that topic is so broad Robert Breedlove has a 453-epsiode podcast channel discussing the subject.
So please accept the 10 episodes I point you to as a quick summary, carefully selected by myself after 1000's of hours of research into the subject. You're welcome.
Example: Why is gold better than fiat currency? Because the government can't print more of it, thereby devaluing all the currency you possess. Sure, there's much more detail than that (on both sides), but the basic proposition can be stated in one sentence.
So if you can't say that for crypto, then it does sound like you don't have a very strong argument.