The licensing process helps make sure that the electrician that has 10 years of experience in El Salvador understands American wiring codes and practices before he does something that'll burn your house down.
For sure there are common skills that all electricians share regardless of country, but there are still significant differences between countries, like in the UK ring circuits are common, but are against code in the USA.
licensing process that doesn't care about relevant unlicensed experience
The problem with unlicensed experience is that it provides no assurance of knowledge of code or safe wiring practice. Like when I found that my house had several MWBC's, but on one of them, the previous owner (or someone he hired) had replaced the tied-handle breakers with untied breakers, which leads to a very unsafe situation (another common mistake with MWBC's is moving breakers around and putting the hots on the same hot leg, which can lead to an overloaded neutral). Or worse, when I mapped out my outlets and found that the owner had put a 30A breaker on the 12 gauge wire leading to the garage outlets, presumably he was tripping the code compliant 20A breaker and "solved" that with a bigger breaker.
For sure there are common skills that all electricians share regardless of country, but there are still significant differences between countries, like in the UK ring circuits are common, but are against code in the USA.
licensing process that doesn't care about relevant unlicensed experience
The problem with unlicensed experience is that it provides no assurance of knowledge of code or safe wiring practice. Like when I found that my house had several MWBC's, but on one of them, the previous owner (or someone he hired) had replaced the tied-handle breakers with untied breakers, which leads to a very unsafe situation (another common mistake with MWBC's is moving breakers around and putting the hots on the same hot leg, which can lead to an overloaded neutral). Or worse, when I mapped out my outlets and found that the owner had put a 30A breaker on the 12 gauge wire leading to the garage outlets, presumably he was tripping the code compliant 20A breaker and "solved" that with a bigger breaker.