How do I defend crypto when I’m put on the spot?

Now I don’t like talking about crypto to others, my family every now and then but only my brother.

But my dad finds it amusing I’m into crypto and has the urge to tell everything that breathes I’m in into crypto. (I’m 17)

And one night, we were at people’s house I’ve known my whole life, they are kind people but I’m not close to them.

And my dad made a joke that Lego (the toy company), makes a crypto coin. Then he looked at me and says how I’m into crypto.

Anyway the dad of the family bursts out laughing about how bad crypto is rn, (it was during the FTX crash).

So they wanted to know why I’m into crypto, and I explain, it goes quite good. Respectfully and kindly explaining, then my dad pulls the, “It’s a Ponzi scheme” And I just froze, I handled it like a champ.

But I didn’t know what to say, while most shitcoins are Ponzi schemes, and while BTC may look like a Ponzi scheme.

It’s really not a Ponzi scheme, and serves a greater use than sucking money into new investors.

Let’s hope I don’t have another conversation like that again, but say it does. What do I say? How do I defend crypto? It’s much easier to imagine slamming someone with points about crypto, but on the spot is much harder and every person is different.

Like I said, hoping it doesn’t happen again. But say it does, what do I do? What do I say?