and you require a whole OS. I expect browsers to outlast OSes. Browsers ran on MacOS 9 and software that ran on those browsers still runs today. MacOS 9 itself, not so much
And sure, when talking about an OS that's often made a point at cutting off support for old binaries it's not good. You're ignoring the fact I can still run a lot of 30+ year old software on modern Linux and often modern Windows with ease.