I did port forwarding in 2010 for a Minecraft server. Basically every router supports it.

It wasn't meaningfully more difficult than setting up the server.

You can't do that with CGNAT.

Most isps, you can’t do that anymore as you no longer have a publically reachable IPv4 address. It moved the ‘just configure your router’ part to their equipment, as they now use CGNAT.

It’s gotten much worse.