Short answer:
Russian inscription: "Well, must".
Unfolded answer:
I'm trying to make an alternative to the Sims. In the Sims, everything grows, including trees. But only in steps (stages). If it is possible to make smooth growth, it will give a huge competitive advantage. It's always important how briefly you can describe a game.
— It's a Sims-like game.
— What's the difference?
— And there's smooth growth!
It's very important that it's visual, that is, that it's an immediately noticeable difference.
Can't they just be there and sway in the wind like normal game trees?
Swinging is well implemented in TreeIt. In other plant generators, as far as I understand, there are problems with it and everything has to be done manually. It is quite a lot of work. And there were also blanks for different tree species quite recognizable.
These are two big pluses that this program had.
Odysseus Doing a classic L-systems plugin for vegetation generation wouldn't be too hard
I don't doubt for a moment that a math programmer can make something like a tree. But if you show the result to a botanist, he'll start cursing foully and might even try to punch you. I wouldn't risk it.
although I'm not sure there's a real need to have it in the engine.
In general, there is a reason to make your own ecosystem and infraxture in the engine. It makes the job of making games a lot easier.
Odysseus Your demands are too high for an anti-totalitarian
Anti-totalitarians have higher requirements, in principle, than adherents of totalitarianism. Under totalitarianism, life is easy and pleasant: there are always rules about how to behave, what to say, and how to act — you don't have to think for yourself and make decisions. This is very attractive to people. Even "in the West," as I learned with surprise. And especially in the US. To a much lesser extent in Europe.