NAT has it's place - where you're shielded from external sources for the basic side of things, apart from not consuming scarce real world IPs too.

CGNAT, or Carrier-grade NAT is a different kettle of fish. I usually just get a static IP with my existing ISP to lessen the traps but with current ISP they buy their IP blocks from a third party, and they are quite expensive per month so i chose to stay with CGNAT instead.

The way that technology is improving there are ways around CGNAT for things you need to run as a local service - i basically haven't hit a hurdle / gotcha as per yet.

I use a CloudFlare Tunnel on Opnsense to link and integrate my Home Assistant server with Alexa/ Tuya et al.

I use a dynip ipv4 checker for my PBX and do that via DNS records on a specific hostname to get around it.

And tailscale to link my servers so they can talk on a network layer that isnt restricted though private and secure.

When out and about, I can use my mobile phone to tailscale into my home network and make use of the local NAT too including manually turning smart devices on / off - that is, lights, aircon, washer, dryer, vertical blinds, TVs etc.

Thanks for the post there brother. I learned something new today!