But I don’t really understand why gold has so much value, so maybe it’s not really a good answer. It’s kind of like saying “Maybe Bitcoins will have value for a long time just like this other non-valuable, non-transaction asset that’s had value for a long time”...
The not oxidizing and rarity are key. E.g. platinum is also not cheap.
Aluminium is close but it's orders of magnitude more common, and still oxidizes a little.
Sadly, the only property it shares with gold is that it's hard to move. In fact, Bitcoin Cash is functionally identical to Bitcoin and it's easy to move.
That's ignoring the hundreds of other digital currencies not named Bitcoin which make a better "digital gold".
The proof that Bitcoin was intended as an alternative to cash, and to be used for small, everyday transactions is right there in the name: It's Bit"coin", not Bitgold, or even Bitbill.