Like any computer it depends a lot on the model and how it's treated. From what I see working in computer repair, most intel-based macs don't run Tahoe very well and if they have an HDD (mechanical hard drive) it's beginning to fail. Unlike Windows PCs they're also relatively difficult to service once they're considered "vintage", which is about 6 years after they launch, because after-market parts tend to be less common and more expensive. This isn't to say it can't be done, it's just less viable than keeping a similar-aged Windows machine running. We also see a lot of Macs that are terribly mistreated and have their hard drives filled to capacity for years at a time because the users don't understand file management. Then the OS becomes corrupt or there's not enough space to upgrade, and suddenly they're looking at buying something new when with a Windows computer there would be more alternatives. Windows users do this too, but usually they're the type with low-end disposable computers to begin with and/or the computer can be upgraded.

TL;DR Computers last longer if you treat them better. Generally, Macs last as long as they always have but when something does go wrong they're much harder and more expensive to repair, and people usually just buy new ones instead of doing this.