Vegan hotdogs are honestly fine and good enough. Thinking back to when I ate meat, I'd rather have a vegan hotdog than a budget one made from who knows what.
And pizza and pasta are quite amendable to being vegan without substitutions if one wishes- don't add cheese and you're done?
So the oyster is a good showpiece to replace, if you can do it successfully.
I still think the whole fake meat business is misguided, but I ranted about that in another comment.
I personally enjoy the oysters at my local fish shop, when i happen to be there on their 'oyster day' and they have them laid out on ice. If it weren't for that, oysters would never enter my psyche; I've never been at the supermarket thinking damn I'm really craving oysters. And if I did happen to see a bag of oysters next to a bag of foysters in the freezer section, you can bet I'm not buying either. I cant be alone on this.
In a supermarket, oysters don't fit. There is nothing exclusive or sexy about most grocery stores.
But when you're at a nice restaurant terrace hanging out over the ocean, and you receive a large sculptured platter of ice with 6-12 oysters on the half shell, garnished nicely, it is a special thing. Coke vs champagne.
What's next, plant-based fugu based on the reasoning that it 100% eliminates the possibility of tetrodotoxin poisoning? Part of the reason puffer is considered a delicacy is there's a non-zero chance it could kill you. Not because it is so yummy.
Oysters are fleshy slime balls, and I'm able to get past the texture and actually enjoy the taste because of some je ne sais quoi. Slime grown in a lab and artificially flavored does not share the same mystique.
But the whole reason that these niche "delicacies" are expensive and sought after in the first place is pretty much solely due to their uniqueness and rarity, not because they have some intrinsic amazing flavor. It's like I can replace diamonds with cubic zirconia, but that ignores the reasons people buy diamonds in the first place.
As for flavor, I can attest that good oysters have a distinctly nice (if acquired) flavor. Two to three chews, then a swallow. Served chilled.
Diamonds, on the other hand, only have a legitimate industrial use. As a "precious stone" they are not legitimate and only appear as such because of marketing and lots of terrible tactics. And for industrial uses, manufactured diamonds are superior. So this isn't really the same as oysters or other consumables.