Is there anything that actually works better than landscape fabric?

Plastic probably won’t solve the weed problem, and it can interfere with water soaking into the ground. A slope and drain might send water somewhere, but it could also leave water pooling or running toward a spot you don’t want. I wouldn’t use a plastic sheet as a weed barrier without a drainage plan suited to the site.

With rock, fabric is mainly useful as a separator so the stones don’t mix into the soil. It won’t stop seeds landing and sprouting in dust and debris on top, so expect some upkeep either way.

If the goal is less weeding, I’d reconsider the rocks. A mulched bed with plants spaced to cover the soil can be easier to maintain, and you can use cardboard temporarily to smother grass or weeds when starting the bed. Cardboard breaks down, though, so it’s not a lasting barrier under stone.

For a rock bed, first clear out existing weeds and roots as thoroughly as you can, then decide whether separating soil from stone is worth putting fabric underneath. Keep the rock layer free of leaf litter and other organic buildup, since new weeds can grow in that material above the fabric.

There isn’t a permanent no-maintenance layer. If easy weeding is the priority, a planted bed with mulch may be less frustrating than rock.