Fair.

Intent - what someone wanted or expected the system to do.

Purpose - what the system does in practice. The reason, or primary function for it.

Some classic examples -- post it notes were intended as a aerospace adhesive, but found their purpose as low tack papers.

If you want a classic systems example, standardized testing is a good example of difference between purpose and intent. It was intended to be a mechanism for measuring schools and ensuring every kid got an equal education. But now its purpose could be described as the metric schools game. It narrows curricula, encourages teaching to the test. Those outcomes are not the original intent. Or even desirable.

So I wasn't being flippant (maybe a little flippant) when I was saying intent and purpose are different.

Other classic examples -- the US senate, social media algorithms, animal bounties (paying people per head bounties on killed rats, frogs, or snakes results in people breeding those animals), war on drugs, zoning laws, etc.

It's very closely related to the idea that "the road to hell is paved with good intentions".