They come in a variety of shapes and forms and dosages - gummies, pills, transdermal delivery, immediate release, sustained release, nasal spray, sublingual, etc.
They are not sold as a 'daily' (or nightly) sleep aid, with the implication that they must be taken daily. There is no suggestion that you should take one a day religiously and the advice is not to take them long term (for more than two months), to seek medical help to deal with any underlying problem if they're still needed after several weeks of use. The directions generally say not to take more than 5mg in 24 hours.
Fwiw, you can buy paracetamol/ acetaminophen in quantities of 500 in the US. The advice is not to take it for more than 10 consecutive days, and not to combine with alcohol.