Very tangentially, "iatrogenic" is a nice niche vocabulary word: Something unintentionally caused by a medical activity, usually undesirable.
My wife has one kidney and as such is told to avoid NSAIDs as a class of medicine. She’s realistically fine taking it every so often but her doctors are asking her to avoid using kidney capacity that could hypothetically be needed to filter and excrete something else.
Acetaminophen/Paracetamol is great alternative for her since it’s processed in the liver. However if you’re a frequent drinker, have a liver deficiency, or have to take some other drug straining your liver, it’s contraindicated.
For most of us most of the time you’re completely correct though.
In the case of these nasal spray decongestants I had a case of rebound congestion due to over-reliance on them while surviving some family bringing really bad colds into the house and my son starting daycare. It was really bad. I then managed by switching to an alternating schedule of pseudoephedrine and the nasal spray so I could reduce the physical dependency on the latter and get a good night’s sleep.
My doctor eventually cleared me to take an allergy spray medication (Fluticasone propionate) that is safer for long term use but generally not used for colds because it inhibits immune response and mask the symptoms which can cause new infections and hurt your ability to heal. Yet another case of the mundane medicine that is contraindicated. While seemingly being the wrong thing to be put on while fighting off infections it worked out great.
After four months I had seen enough child germs and no adult has brought their own plague or food poisoning (it was a very bad summer for me) and I finally became healthy again.
What many people don't know: Overdosing on paracetamol is the leading cause of acute liver failure. It's also contraindicated for people with Gilbert's syndrome, which is actually pretty common (~5% of people in the US) and most people don't even know they have it, as it's harmless and usually only found accidentally through high bilirubin levels in the blood.
If there was a way to somehow sum up all of the suffering caused by these sprays from dependency (which lasts weeks, months, years even) and compare that with the suffering alleviated from a cold (which lasts a fews days), my bet is these cause more harm than good.
Many people have used decongestants so much they cannot quit them or will have to suffer weeks of nasal congestion. I risked going through that; later I swore I will never touch one ever again.