My router gets push software upgrades, but you can turn that off. I’ve just changed the configuration though so that it will only install sw and and reboot in the middle if the night, not at any old time, since the reboot is disruptive. At least it only takes five seconds, maybe less, to reboot.
In contrast, my ZyXEL WAPs take over three minutes to reboot, and my ZyXEL VMG 1312-B10As take over minute iirc.