This is true for the US as well. It’s why legal immigration into the US isn’t as easy as people would try to pretend. Other than a student visa, you are required to have a sponsor. Whether that be a family member or significant other that can support you, or a place of business that is going to be paying you a salary so a person can support themselves.

There are also limitations based on country of origin. Some countries don’t have that much “competition” when it comes to people applying for citizenship, so they can get through the process quickly. Other countries have huge populations of people attempting to immigrate, causing year of delays on processing paperwork. That is why “illegal” immigration is so common in the US. The process is bogged down in bureaucracy and paperwork, all of which generally require time/money/legal representation. Something a majority of US citizens could not afford if they had to do so to stay in the country.