It's unfortunate you're being downvoted. Your intuition is spot on. Here's [0] a report from the Danish Environmental Protection Agency about life cycle analysis of different shopping bags. See table 4 on page 18 in the summary. A cotton bag needs to be reused 7,100 times and an organic cotton one even 21,000 times to reach parity in its environmental impact compared to a single use plastic bag that's reused as a trash bag.

There's plenty of other studies. Just search for life cycle analysis of grocery bags or similar on Google Scholar.

[0]: https://backend.orbit.dtu.dk/ws/portalfiles/portal/151577434...

This is a myopic view.

My state recently started charging for bags. Guess what? People carry groceries in their hands when possible. Many bring their own bag plastic reusable bags.

It’s not just the energy required to create them. It’s that they’re virtually indestructible. They litter. They fly away. They break and leak plastic everywhere in the environment leading to microplastic found in blood of wildlife.

And this is just scratching the surface. I know it sounds like an educated view and it’s not entirely wrong but there’s more to it than what appears. Plastic is a problem and the less of it we use the better we and our next generations will be.

A little part of me (and the planet, I suppose) dies whenever my wife uses one of those thick plastic reusable bags as a bin bag.