I am very indicative and see pros and cons for all subclasses like circle of land is more tank and spellcasty moon is focused on wild shape circle of dreams, Shepard and spores have pros and cons as well
I don’t think and subclass is better than the others. They’re all fun to play and they all have different strengths and weaknesses. Each one is the best one depending on what you like and each one is the worst depending on what you like.
I’ve wanted to play a lyncanthrope for years and I’m kind of doing that with a Moon Druid, but the thrill is the shapechanging, not the power or lack of power.
Its playstyle and level dependant / game dependant (you arent much use as a moon druid at low levels if animals are extinct)
Moon at 2nd to 3rd a is fight winner due to the Hit point sink. then they slump, At 10th level they can become functionally immortal and will destroy nearly any game soloing the vast quantity of adventures with nothing able to stop them - but shouldnt do it because it makes the party pointless.
Shepherd at 2nd grants temporary hits when you get up, as long as you have a long breakfast after the shepherd can then heal more than anything possibly should - unicorn totem allows you to heal every friend in a 30' radius any time you use a healing spell slot. Its frankly ridiculous. When you reach 6th you begin conjuring creatures as extra meat shields and that tasty healing totem heals them, then later they heal automatically if there in the totem radius. Its amazing.
Land - nice extra spells, chosen wisely you increase your utility immensely Immunity to poison and disease means you should be milking poisonous animals, drinking the stuff and applying to your weapons. Its the basic 'judge every other subclass from this' option.
Dreams - a healer and something... Look the shepherd heals more making this a less desirable option unless you love the flavour of a fey court druid.
Spores - you fell in love with Myconoids. Can be good or tiresome as all heck to play. - You can gain an army of zombies, you most likely wont. You can deal a lot of damage with poison if your close to the front but not being hit too bad you have to retreat. Its new, its fun, but its really weird.