License texts are copied billions of times every day.

In most cases, accompanying software by unpaid open source developers.

- Are there cases where such a person has been sued due to some warranty-related aspect?

- Could you be sued if you forget to add a license?

- Is the entire section pointless?

A related concept is liability. Suppose you're a service provider - a contractor who performs maintenance services. You sign a contract with your client, BigCo, where you will service their plant's fancy $1m machine every month, and in return they pay you a modest $500 per month. One month you make a mistake in your work which causes their machine to become defective, but you & they don't notice in time before the defective machine creates a large mess. The defective machine causes BigCo to lose $3m due to lost revenue while the machine is offline & their costs to replace the machine. There's a pretty good chance BigCo may be able to sue you for the $3m losses they suffered from your mistake, even though this is disproportionately higher than the value of your $500 / monthly fee. As the contractor you avoid or limit this by making sure there is language in the contract to limit your liability & maybe arranging an insurance policy.

Now, how do things change if you sell a software product instead of a service? & how do things change if you give that software product away for free, instead of selling it? There's still a chance that some user of your free open source software product suffers real harm because of it. Particularly if they're using your free software in a commercial context with a lot of scale, perhaps they've suffered millions of dollars of losses because your free software product was defective. Are you liable to compensate them for their damages? Maybe!

Basically, it means that the developer does not guarantee that the software works, because in some countries or jurisdictions (like the US) it is assumed that the developer provides a "warranty" that the software works unless the developer explicitly says otherwise.

So basically, it's like saying "you can't sue me if my software has bugs"

What county!

The USA has complex warranty laws and that text has specific meaning and limits what it allows them to not warranty. Other counties have different laws. See a lawyer

Your best bet is to look up case law of a specific license type in your jurisdiction. If you're using GPLv3 or something common like that, then you should be able to GoogleFu plenty of case law on in.

If it matters, hire an attorney. If it doesn’t matter, it doesn’t matter.

https://www.law.cornell.edu/wex/warranty_of_merchantability