There's a lot of truth here. Some Apple products (such as the iPhone and the iMac have attained a state of near-perfection, and it gets tougher and tougher to improve on that. Plus which, Apple products are notoriously rugged and you can count on them to have long lifespans. Now, Apple (like everybody else in the industry) has made a lot of money out of inducing purchasers to accept the premise of a three-year replacement cycle for computers and a one-year cycle for smartphones. But this old notion is getting harder and harder to sustain, plenty of folks are willing to hang on to their present stuff until Apple is able to produce updated replacements that are genuinely more desirable, or, failing that, that can at least run operating systems and maybe other software with genuinely more desirable features, which cannot be run on their present devices. This change in purchasing habits is going to revolutionize the economics of the entire industry and is creating certain optical illusions
One example of what I mean is that decreasing (or in the case of Apple leveled-off) sales of desktop equipment has induced some self-appointed pundits to write the obituary for desktop computing. Nuts. Just because purchasing habits for desktops are changing does not necessarily mean that desktops are being used any less than they ever were, just that the same desktops are staying in use longer. I have no doubt that same is about to start happening with smartphones, if it hasn't already. There are still plenty of Apple products (such as the Mac Pro, the Home Pod, the Watch and Air Pods) which can stand a whole lot of genuine improvement before they enter a similar state of near-perfection, and it is such products that I expect will continue to produce healthy sales figures for years to come.