Problems are international calls are already in a technically deficient state. e.g. caller IDs are not sent properly and a generic dummy is sent. Telco 1 uses Telco 2 to connect to Telco 3 which finally terminates on Telco 4's network and rings the phone.

There are literally treaties that govern phone traffic that would have to be updated. Most telcos are a monopoly or oligopoly and don't care about customer dissatisfaction. It's not like there's a substitute to the PSTN ready to go. Are you going to tell all of your contacts you are only reachable through Skype/Hangouts/Facetime? Cutting off a spammy foreign telco would also hurt revenue.

Frankly, the definition of telecom fraud should include corporations ripping off their customers not just petty criminals getting free calls.

You can't just remove this - it's a legitimate use case.

For example if you go to another country with your mobile phone, your call will be international, but the caller id would not match the source.

But there are plenty of ways for my phone company to verify that it was my phone. (they might verify a clone of my sim, but that is a different problem that they already have to handle)