Uniswap v2 will only give you a price feed for ERC-20s; it won’t help with feeds for these currencies.
I would say this is most analogous to timestamps, which can’t be verified programmatically and depend on subjective facts about when messages were propagated to the network. Similar (despite the mitigations you mention) with censorship, PoS forks, data availability attacks…
The benefit of having this in the base layer is developer confidence that their contracts can rely on it existing forever. Oracles are one of the few intractable sticking points that force a project to include some upgradeability or governance.
On the flip side, I do admit that the social commitment for validators to operate this oracle forever is quite daunting and maybe a dealbreaker.