1 bitcoin is its own thing
2 bitcoin has a clear analog in the form of gold
Collectibles are a terrible analogy because
1 they are not fungable and bitcoin is
2 they are not easily converted into currency whereas bitcoin is
3 they carry novelty and bitcoin does not (cryptocurrency may carry some novelty but each individual bitcoin does not).
4 their value is based on nostalgia turned speculation whereas bitcoins is more complex (though still speculative)
5 neither is really good for anything other than maybe as a value store (though both are questionable on that front too)
I could go on. Gold is genuinely a pretty good analogy for bitcoin. People buy both believing they can be converted into money later or directly traded. Both have pools of true believers, spectators and novelty purchaers. The main difference is simply that bitcoin does not have the long history that gold does.