I would like to start by saying that a huge thing that makes Bitcoin not like "other cryptocurrencies" is that Bitcoin is a social construct of community design and consensus much like a digital version of the Isle of Yap stones (https://en.wikipedia.org/wiki/Rai_stones) whereas "other cryptocurrencies" are created by companies with venture capital funding and complete control over the protocol much more akin to company scrip (https://en.wikipedia.org/wiki/Company_scrip) or company shares (see comments from SEC chair Gary Gensler) than something a society would one day call money.

To that point, Bitcoin can be about belief and faith at first: https://www.youtube.com/watch?v=EPspYa8TLlA (faith). To explain how this faith in money is not the same faith one might have in religion, I would go back and point out that Bitcoin is a social construct and like the social construct we call "family" although some people believe family can only ever be biological, the idea behind the social construct of family is that family takes care of each other when the members within it are struggling and for that reason other people believe family can be just people who raised you, or even complete strangers as people find a new "family" within their social construct of what a family is even into their adult life.

To come back to your initial curiosity though, saving money is a real use case of money. For other examples, you might look to "bitcoin beach" wherein the use case was to make purchases of local goods for visiting tourists easier.

I just really wanted to drive home the point, that technology is not enough. Technology is not all that makes Bitcoin what it is. The social layer of Bitcoin can not be ignored as it is a huge part of the reason Bitcoin can not just be copied.