[cywick]

The main issue is, as the article points out towards the end, that you only receive all macOS security updates if you are on the latest major version. The two major versions prior to that one receive some, but not all, security updates. Once you are three major versions behind, your Mac does not receive any macOS security fixes anymore, which of course is hugely problematic.

So yes, unless you are completely ignoring the security of your system, losing macOS support is a kind of soft kill switch for the hardware.

[dereg]

There's another way which you could see this, which is that the cost of maintaining backward compatibility for every prior piece of hardware only increases the surface area for vulnerabilities to emerge.

Also, if security is your #1 priority you should pay the cost of the upgrade. Monterey is compatible with Macs as old as 2015. That means that Apple will sunset security support for it in 2024. That's nine years of supported life for your computer – not bad.