Xfinity these days will have the tech set up your WiFi with your password. It's an integrated device so he'll set up the cable internet and then your WiFi. Monkeybrains is all "you're set up!" and then you add your own WiFi router. Sonic has you set up your own WiFi. AT&T has the WiFi password printed on the device along with the admin password.

That's my experience with ISPs in SF. It's clear that many people don't buy Internet access. They buy "WiFi" which is that Xfinity integrated service. The components don't matter.