I think Unreal is often misunderstood like that- that being unreal is only good for AAA/AA games. A lot of what makes Unreal great for AAA/AA also makes it good for indies- everyone’s making a game, no matter how much money is getting pumped into it.
It isn’t necessarily easier to make a simple, stylized game in Unity. Although it is easier to make photorealistic in Unreal thanks to quixel and lighting with a very high starting bar, that doesn’t mean it’s harder to make stylized games.
Just consider looking into tutorials on how to get the kind of look you’re going for. Things like auto-exposure wouldn’t necessarily go well with that kind of look.
You can make great looking games using either engine, but I’d recommend just sticking with Unreal at this point. There aren’t any glaring reasons one is better than the other for that type of game, and you’ve already started learning Unreal.
Not necessarily exactly what you’re looking for, but the channel PrismaticaDev is handy for learning specific things you may want to know. StylizedStation is nice too, but it’s pretty hit or miss.