pharmacology - Why is Paracetamol so great?

Paracetamol is a pain killer, it does not treat the cause of your illness, it only alleviates the symptoms. From its wikipedia page:

Paracetamol [...], chemically named
N-acetyl-p-aminophenol, is a widely used over-the-counter analgesic
(pain reliever) and antipyretic (fever reducer).

So, paracetamol does not make you better. Your immune system makes you better. Paracetamol just makes you feel better while you are waiting for your immune system to get an infection under control.

You should be aware that it is only safe in small doses and a toxic dose is not that much more than the recommended one (source):

Risk of severe liver damage (ie a peak ALT more than 1000 IU/L)

Based on the dose of paracetamol ingested (mg/kg body weight):

Less than 150 mg/kg - unlikely
More than 250 mg/kg - likely
More than 12 g total - potentially fatal

Again from wikipedia:

While generally safe for use at recommended doses (1,000 mg per single
dose and up to 4,000 mg per day for adults),[6] acute overdoses of
paracetamol can cause potentially fatal liver damage and, in rare
individuals, a normal dose can do the same; the risk may be heightened
by chronic alcohol abuse, though it is lessened by contemporary
alcohol consumption. Paracetamol toxicity is the foremost cause of
acute liver failure in the Western world, and accounts for most drug
overdoses in the United States, the United Kingdom, Australia and New
Zealand.

I am sure someone else can explain the pharmacokinetics and details of action of paracetamol. I just wanted to point out that paracetamol can be dangerous and should be treated with respect.