Yes, tiny fibers that give a garment that softness you love, become fused together and coated from fabric softner/sheets. If you're heavy-handed with them they also leave a residue inside your machines that I think can transfer to fabrics in the next load.
I never used dryer sheets after reading about someone trying to clean residue from the inside of the drum.
I do use liquid softner, but I find I can get by with just a fraction of the recommend amount. I dilute it quite a bit and still have no problem with static, which is my main reason for using.
I dont use ANY softner on the newer fabrics that are, or share properties with microfiber.
I also have very hard water. Many people here use '20 Mule Team Borax' in the washer because of Borax's natural water softening action.
Look for it in the laundry aisle.