Apple Macs are great BUT . . .
(a) they're ruddy expensive ;
(b) there's far less software (especially the free stuff) available for them ;
(c) you need to check that your peripherals, such as printers, will work with them ; and
(d) while they're undoubtedly better at some complex tasks, such as high-end video-processing, than PCs, they're no better at doing routine things (such as word processing or web browsing).
Further, there can be no real guarantees that, in the rapidly-changing world of technology, Apple won't introduce changes at some date in the future which could make older machines redundant.
If I really wanted to 'future-proof' a computer, I'd probably opt for one running a version of Linux (such as Ubuntu) but you still need to be a bit of a techie to really get to grips with Linux. (I reckon that I'm reasonably technically-minded but I'm still only feeling my way around with Linux and I've yet to start using it for day-to-day computing).