It's not complicated, just difficult. Separate waste ...

streams for efficient recycling. Aluminum with aluminum, newsprint with newsprint, clear plastic unpressurized (no fizz) bottles with clear plastic unpressurized bottles. (Pressurized are a much bigger problem because they're made in layers of different molecular structure; bun 'em.)

The problem is that either the producer does this, and the public is both hard to train and hates the task, or the recycling stream does this, and it costs more money than the material is worth unless the labor is very, very cheap.

Take newsprint: it tears easily in one direction, raggedly in the other because the wood fibers are both long and lined up in one direction (the easy tear is parallel to the fibers). It's either make it that way or the modern high-speed press doesn't work because the paper fails. No other paper has such long fibers; those fibers break every time the paper is returned to pulp and reused.

The same is true about almost all other items that are recycled for their material. The gold in electronic gadgets? Deposited in thicknesses measured in atoms and damned difficult to recover because there is such a tiny amount compared to everything else.

Yes, recycling can reuse valuable material, but only if you can separate it. And separating it is labor intensive which is a synonym for "expensive."