Fabric softener is a scam.
Quaternary ammonium compounds, the active ingredient in most fabric softeners and dryer sheets, are documented aquatic toxins.
They kill fish, algae, and the small invertebrates (daphnia, copepods) that everything else in the food chain depends on.
Up to 81% of the chemicals leach into wash water and pass through wastewater treatment plants into local waterways. They biodegrade slowly and contribute to harmful algal blooms.
They also coat your dryer's moisture sensor over time, which makes the machine run longer than it needs to and uses more electricity.
Wool dryer balls do the same job for years. Three to four balls in the dryer separate fabrics, reduce static, cut drying time by 15 to 25%, and don't poison anything.
A set is $10 to $15. They pay for themselves in electricity savings within a few months.
For scent, put a few drops of essential oil on the wool balls before tossing them in. Or skip the scent, since most "fresh laundry" smell is the same chemicals doing the damage downstream.
Your laundry will be soft and the fish will be alive. Everyone wins.