Fair point!
But even if we're thinking about those small scale terrariums that hobbyists make, or those NASA experiments in smallish (like the volume of a few shipping containers) sealed biospheres, there's kind of an art to getting it right, and insects are important. Although you can also have weird runaway effects where one species like nettles or ants takes over everything and then dies out. Sealed biospheres are a honestly great tool for helping to understand how "simple" Earth conditions are actually the result of like two hundred different subtle feedback loops perfectly balancing each other.
...I imagine a lot of this is not 100% applicable because it's our soul, so everything is kind of a metaphor as much as it's a physical thing, like how our crops needed our attention to grow and so on. But I imagine that butterflies and bees to pollinate flowers, worms to turn the soil, beetles to uh... beetle around, and so on, can't hurt in making it more vibrant.
