Not one or the other of these ventures have a substantial use-case.
Im not sure about shiba. it's a defi token right now. Shiba itself already announced that on its official twitter. Shiba has shiba swap and it will be launched shiba blockchain as soon as possible. This may change the image of shiba inu to be a meme token. You can even check it directly. it seems like the vision of shiba inu is much stronger than doge coin. The doge coin must have needed a developer that can at least give it second layer blockchain to make doge coin can be integrated with defi and NFT.
And they likely won’t be around within the next 10 year.
Im not sure about this. doge has been in the crypto almost for a decade. That proves that if doge is having a very strong community that will always back it along with shiba inu with its own community. I personally think that if shiba and doge will be last forever. Im not a supporter of those tokens but the developments are still running. We will see what will be the next achievement that will be achieved by shiba and how it will be competing and surviving for long term.
Shiba now has a large community as well. At the beginning of the release until not long ago shiba inu already has a large following and proved it can boost through high capitality. For the next ten years I think shiba will still be able to fly because this coin is still considered quite cheap and the goal is certainly to reach the same point as the doge.