In reply to Dom.

There's an article on Consumerreports.org https://www.consumerreports.org/appliances/laundry/why-fabric-softener-is-bad-for-your-laundry-a5931009251/

My daughter uses fabric softener, her husband loves it. Their towels definitely are not absorbent. When I'm visiting for more than a couple days, I sneak around and wash some towels for me to use.