That's not how macs work. You don't suddenly lose the ability to run new binaries just because they're not on the latest MacOS version.
Using your own conservative estimate, 8 years seems like a fine lifespan for a laptop, far longer than the "few years" you initially said. And in practice, there are plenty of macbooks that have been running even longer.
Using your own conservative estimate, 8 years seems like a fine lifespan for a laptop, far longer than the "few years" you initially said. And in practice, there are plenty of macbooks that have been running even longer.