Well actually, that's a very current question to me !
I'm using a 5 year old MacBook Pro 15" (with a 1 TB SSD). Loving it since the day I started using it. I was simply overblown by the speed of booting the system and all applications. I updated to macOS Sierra (10.12) and regularly receive security updates for this system version.

Due to my use of older applications like Keynote 5.3 (intensively) and Adobe CS (in which I sometimes still need to train people), I'm still reluctant to updating to Mojave (10.14). But I notice that the integration of my MacBook and the iPhone'ssystem and iCloud features is becoming less reliable. I guess because Apple just doesn't want to be held back with their iOS, and I can understand that. And of course newer versions of applications also don't work well anymore – or at all, but these are just a very few ones, and you can always check their system requirements before installing. (The whole range from Adobe CS3 to Adobe CC 2019 still works with it, except Premiere Rush.)

I wouldn't mind not being able to receive security updates anymore. I'm a very routined Mac user, and the system's architecture is very robust in essence, so I don't expect serious mayhem because of vulnerabilities. A good dose of common sense and tools like Malwarebytes are keeping my system clean enough to work with.

So all in all, there are not so many real risks or dangerous threats, but gradually emerging inoperable versions of software and flaws in the integration of features in newer devices their default systems.

After 5 years the time has come to move to a new machine, with a newer system version, and new concurrent applications. But I think I'm keeping this old one on the side, and expect to be working with it now and then for another 5 more years.

Oorspronkelijk geplaatst op Quora: What are the risks from not updating your MacBook?"