Better Trees is a worldgen datapack/mod that completely redesigns the way that overworld trees. Vanilla biomes feel new and more complex, and it works well with overworld worldgen packs/mods such as Tectonic.
Trees in this datapack are generally taller, and more complex looking than their vanilla counterparts, but still feel somewhat vanilla.
Cutting one down will give you more wood and saplings, but since many of them are really big, I recommend a tree cutting mod, such as Timber datapack or FallingTree.
For more general biome improvements, check out Wilderness.