New plastic doesn’t have that problem and is incredibly cheap.

Take price as a proxy for resource / energy input and see that new plastic is also incredibly lite on inputs.

New plastic may have some off-gassing / contact contamination concerns though.

Last time I checked, energetically we’re better off using plastic over paper or recycled plastic, and burying the waste… if we could do that reliably, which we don’t seem to be able to.

There are several separate problems here.

One is "People don't like bags stuck in the branches of trees and clogging waterways in their parks". Lightweight plastic shopping bags are so thin that a light breeze can pick them up and loft them up into the air easily. They cost approximately nothing - <2 cents retail, significantly less in bulk. It is incredibly expensive by comparison to pay someone to remove them from tree branches and riparian zones - tens of dollars in wages, equipment, and liability insurance. This is a pragmatic reason why municipalities passed bag taxes or bans. Forcing people to use paper or heavier-weight plastic bags that don't blow in the wind, even if they're not in practice "reusable", solves this one. Taxing them 5 cents or 10 cents or 25 cents per bag nudges a high percentage away.