Naturalization in Europe is restrictive if you measure it across all axes:
- Allow time-based naturalization outside of marriage?
- Allow dual or more citizenship?
CH is on the more restrictive end, but it is one of the few European countries to allow either of the above. If you compare outcomes and hurdles, the U.S. has been more restrictive to foreigners coming in than CH (don’t believe me; tell that the the Canadians I know who moved to CH instead of working for U.S. branches due to U.S. not issuing family reunification visa).
So the question to ask: what do you want? Permit to enter, live, and work; permanent residency; citizenship? Each of these things are different.
I don't think "extremely restrictive" is the right word.
If you're an EU citizen you have the right to live there no questions asked.
If you're not EU, you can live there to pursue gainful employment so long as your employer can show that you have skills they can't obtain from within Switzerland or the EU.
If you can get a job, you'll be given either an L permit, which is "temporary" but can be exchanged for a B permit after 2 years, which can then be renewed indefinitely. After 5 years, if you can demonstrate integration (criteria vary by canton), you can get a C permit, which is permanent (essentially a green card).
As a skilled worker, I actually found Switzerland to be substantially more friendly than the US, though a lot of the hard work was handled by my employer.
Switzerland is restrictive with naturalization. You can be born here, have spent your entire life here, and still not have citizenship.
Due to bilateral treaties, immigration from EU countries is quite easy nowadays, but for citizens of non-EU countries, far less so. Almost 90% of resident foreigners are European: https://en.wikipedia.org/wiki/Demographics_of_Switzerland
It was super easy for me to get a working visa to Switzerland when I had a job there, and I’m not EU. Anecdata for sure, but I was hardly the only non-European around. There were even plenty of war and economic refugees around, far more than I ever encountered in the states.
