So that just leaves these rubbish Natural Wonders:
Chocolate Hills
Gobustan
Pantanal
And these disappointing ones:
Ubsunur Hollow
Mount Everest
Lake Retba
Hopefully a few of them will get rebalanced too. A good test would be to double the yields on them and think if they would be OP or not
Chocolate hills - 1f/2p/1s -> 2f/4p/2s: okay, that would probably be a little strong, but not a ton better than a good Torres del Paine spot, worse even still given you can't improve them.
Gobustan - 3c/1p -> 6c/2p: I mean, even at a 6 culture tile, that's not a lot better than the best Paititi-tile, and Paititi is only a bonus onto base tile yields
Ubunusur - 1f/1p/2fa -> 2/2/4: Not OP in the least. It's a good yield for the tundra, but not even a great yield for a tile compared to some
Everest - 1fa to adj -> 2 fa to adj: Like the Matterhorn, the yields are minor compared to the bonus. But even the bonus is just ok. Matterhorn you get a combat bonus and movement bonus, feels like Everest they could easily do something like "apostles gain a promotion moving next to Everest", and yeah, that would be strong, but still highly situational. Or perhaps at least it should give all religious units moving next to it a +5 combat strength, or an extra charge.
Retba - 1p/2g/2c -> 2p/4g/4c: doubling it would certainly make them strong tiles, but the lack of food doesn't make it a crazy yield.
Otherwise, it's still hard to balance some wonders like the Dead Sea or the Matterhorn, which have low yields, but a solid secondary effect. And I don't think every tile needs to be "fountain of Youth/Paititi"-level strength. But yeah, all the ones you listed at least are ones where I see them and are like "okay, cool. So what was I doing before?" rather than the ones like Torres, Galapagos, Great Barrier Reef, Eyja..., etc where I see them and immediately think if I can find a city spot nearby to make use of them.