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.
In my case a downtime of over 4 hours will switch it. Might just be lease time doing its job.
This is simply called the dhcp lease time. Restarting has never forced a change of ip on a system using a dhcp client.
True, I've had the same IPv4 address since 2018 on Spectrum despite rebooting at least 10 times.