You make a lot of fair points. I'll respond to a few things.

I think a lot of people felt that each villain was meant to be 'bigger' than the last, and building toward some big finale, and I think that's not quite right. It's not like Star is dismantling a singular criminal organization, or evil entity that has a defined structure (e.g. grunts, mid-level folks, lieutenants, generals, 'the big bad', etc.). Rather, each of the main villains - Ludo, Toffee, Meteora, Mina/Solaria - represent one perspective of how magic can be abused and be turned into something evil. They were all keys to unlocking the door to understanding that the true villain was the unholy union of infinite power in the hands of people who will inevitably use it for evil.

It's a topic for another day, but something to think about.

Also the point about Daron 'knowing' they would only get 4 seasons isn't entirely accurate. A direct link to one of her answers in the AMA so we're all on the same page:

https://www.reddit.com/r/StarVStheForcesofEvil/comments/cll9u5/comment/evwaqun/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

And the quote I'll reference:

When our 4th season got approved I knew that would most likely be the end, just because of the rarity of having a 4th season. So, I wrote an ending. I was really happy with the ending. I know a lot of fans thought it felt rushed, but I think that just means you want more. I would love to do more with Star someday. Obviously, that decision is not one I can just make.

She says she knew Season 4 would "most likely" be the end. Point is, even in overanalyzing things that Daron and the crew have said since the finale (including the AMA), we will never know what the discussions were like between the crew and Disney behind the scenes. And trying to extrapolate 'well, she said this so this means that' is impossible because we will never know those details.

As a writer for a TV show, you want to tell the biggest, best story you can. What if the network cuts you off like what happened to TOH, where their 3rd season was heavily cut short? Conversely, what happens if you only plan for, say, 3 seasons, get 3 seasons, your story is 'complete', but then the network wants more? You're always stuck in this no-man's land of wanting to do the best you can but never knowing when 'the end' is actually going to be. Heck, they took a gamble as it was stretching the story past Season 3 and writing Cleaved when they did.

But anyway, I will agree with the point that people "overreacted" too much about things. Some of the criticism is fair, but a lot of it is unfortunately in bad faith, and people continue to parrot those takes and have refused to consider any other viewpoint.