The majority of expats here do not have residency though it will probably be more necessary in the future. You can go to CR or another country every 90 days (180 with an extension).
Amy and I have residency and are considering becoming even citizens now. With residency you can have a vehicle (without it you can purchase a vehicle but you cannot register it). Residency avoids the need to leave the country, own a firearm, have a phone plan, carry your passport and a few other things. You can start a company and buy property without residency.
So there are advantages but most expats do not have residency. In fact, I believe there are only 1200 expat residents in the country.
Regards
Darrell