That is entirely ISP dependent and many don't actually work like that. Your cable modem gets a specific IP for as long as Comcast or whoever sees fit, restarting does nothing on the WAN side.
True, I've had the same IPv4 address since 2018 on Spectrum despite rebooting at least 10 times.
True, I've had the same IPv4 address since 2018 on Spectrum despite rebooting at least 10 times.