I love Po3, I really do. It's my favorite arc, I think it was amazing.
But... the Prophecy of Three is... bad. I don't really think it caused too many issues in Po3 itself, since that series ended up being more about family in the end, which I really like. But after it gets moved to OotS, we really see all its failures right there in broad daylight. It just... was not handled well at all.
First, Hollyleaf:
It's pretty common knowledge that Hollyleaf wasn't included because the authors straight up couldn't think of anything for her. This wouldn't be a bad thing if it was not common knowledge. I really like how that fact gets revealed and the personal issues she goes through because of it makes a really good story, regardless of how it came about. But the authors have always just been like "yeah, we just couldn't think of anything, sry", which makes the arc be viewed in an entirely different and worse light by the majority of the fandom.
Second, Omen of the Stars as a whole:
Despite Power of Three having the title it does and the Prophecy of Three having the name it does, OotS is really the arc where the Prophecy takes hold, and OotS is what I affectionately call a goddamn mess. Don't get me wrong, I love this arc, but it's so messy. So messy. From inconsistencies to nonsensical scenes to forgotten plot points to useless characters, this arc is just... wow. I found it one of the more enjoyable arcs just because I love the characters, and I actually felt each individual scene was written really well, but I can admit that my second favorite arc is the worst written of the 6.3 arcs we have, and I truly think it's because the Prophecy was not thought out. Dovewing and Ivypool are both wonderful and enjoyable characters that are made worse by the Prophecy. Jayfeather and Lionblaze are both wonderful and enjoyable characters (yes, Lionblaze is awesome, come at me haters) that once the prophecy really got a hold of them, were made worse. Jay always cared about the Prophecy, but in Po3 it was always from a more mystical, spiritual perspective, whereas in OotS, it's just him shouting into the void every other chapter. OotS has general writing problems, sure, but its massive focus on the Prophecy caused a fair bit of those problems.
Third, the final battle:
What's in a recipe jar for disappointment? Two arcs of hype, an ANCIENT prophecy from the guys older than StarClan, three characters with mystical powers (2 out of 3 of which never face any evil temptation), and...
A final battle where only 3 vaguely-important characters die, 2 out of 3 mystical powers aren't used at all, and no grand reveal of the Prophecy.
(Yes, I get more than 3 cats died, but I'm considering Mousefur, Ferncloud, and Hollyleaf the "important ones". Dovewing used her powers like one time to alert the attack, and Jay was completely useless. The leaders and deputies of each Clan were revealed the Prophecy, but the Three never face any adverse effects from this like judgement from their Clanmates, other Clans, etc. Just wanted to clear up the sentence above so no one comes at me)
There's a whole lot of opportunities in The Last Hope. Some are executed very well (the chapter where Jayfeather reunites StarClan is one of my favorites in the franchise), but others are just like... why did you not take the obvious opening here?
And lastly, the sheer pointlessness of it all.
As I mentioned in the last spoiler tag, Jay and Dove don't use their powers to anywhere NEAR their full potential in the final battle. And while Jay's powers are the coolest, their "purpose" is to help in the battle of the stars, which they... don't. At all. The most Jay does in this regard is reunite StarClan, which while very helpful and necessary, doesn't require his powers.
I don't hate the powers. I love the powers, they make the story interesting. Jay's powers, despite not being useful to the battle, and thus not having a "purpose", were THE thing that made Po3 as good as it was, and were extremely important and useful for the plot in that arc, and even in OotS as well. My problem is not with the powers, it's this prophecy that tries to give a purpose to the powers, and fails. Yellowfang's powers didn't have a purpose. Goosefeather's powers didn't have a purpose. This prophecy is not necessary here.
They then decide, hey, the Prophecy's been fulfilled, which means there's no "purpose" for these powers anymore, let's just scrap 'em! I am so against this decision that I stopped reading. The powers were never the problem. This stupid prophecy is the problem.
I really love both Po3 and OotS. I think they're the most enjoyable arcs and have the best characters. I even love what Po3 turned out to be despite its rough time during development. But this prophecy needed to be scrapped. It just did. Or at the very least moved to OotS entirely.
I'm working on a rewrite/AU/ fun idea of Po3, actually, where Jay, Lion and Holly still have powers, but not because of the prophecy. Because they're kits of a medicine cat. If medicine cat kits have too much power within them, that would be a completely valid reason for the no kits rule, and would even make sense for that reason to be kept secret from the modern Clans. But no, as it stands, the reason for no kits is "just cause". I think if MC kits were powerful and the old Clans were scared of them, that would make a pretty good way for Jay, Lion, and in this universe Holly too, to have powers without making it so reliant on the Prophecy. You could even have Dovewing be the sole subject of her own prophecy if you
really wanted that DF battle. Maybe actually do something with that "Dove's gentle wing" prophecy instead, I don't know. Food for thought.
I'm also not looking to get into a debate with anyone on anything here. I realize I just wrote a freaking essay, and I also made a joke about "haters come at me", but really, I'm not looking to argue with anyone, thanks!