It is yours for as long as you want it, and it (mostly) runs all the software it was compatible with when you first bought it (there are some quirks around software you had access to but didn't install, like Garageband, where you may no longer be able to access the original version). Stuff doesn't just 'stop working', as a rule, but the rest of the world does move on. I'm not sure what you think should be done about that? All software should always be backwards compatible with older versions forever?

As a reasonable alternative, you can stick Linux on it and it'll run nicely, although with a different set of software to what you got the laptop with. 2026 is the year of the Linux Desktop!1! (in all seriousness though, it is actually quite good by now).