Comment by wolvoleo

It depends on the country. And Spain is not as simple as you say. Even getting the NIE is very difficult due to the foreign police not making enough appointments available. And expensive immigration agencies hoarding those appointments to make money.

Then you need a social security number exist is different than the NIE, you need empradonamiento, you need to register with the health service and you need to set up your tax if you're going to work here (or if you live there more than 180 days of the year)