Man you'll be floored when you'll learn that 90% of people going online never have a "real IP". Servers see the IP of the NAT's most of the time. ngrok doesn't require an outside-accessible IP.
You're still going to need to set up port forwarding on the firewall of each site you develop at, and if you use DHCP with no static assignment... more fun.
Honestly it depends on your use case, port forwarding and dyndns is trivial to configure, but if you're using development time to do it more than a few times then it's a non-trivial efficiency leak
Anyways my ISP has provided me with a fixed IP for about 17 years.