It's not always that easy. There are family relationships, losing full health coverage, being excluded from expat insurance, taxation issues, where to place your portfolios outside of your home country investment advisors, etc
Malaysia is in the process of cutting diesel oil subsidy by the billions in addition to cutting billions for cooking oil. It has affirmative action policies for 65 % of the population viz., lower entry requirements for universities, easier high school examinations, huge number of civil servants, most of which will not survive in the private sector: mandated that private sector must employ 30% of mostly unqualified natives which make up 65% of the population. Natives have special priviledges considered considered rights that cannot be removed without causing the ruling parties riots and removal from office. Needless to list more.
18:00 French assembly looked into it (Eric Coquerel) and they decided it's not feasible because of the tax treaties and how they are above laws. What they can strengthen is exit taxes and it was the result of Coquerel analysis. Exit taxes are great for countries because they accelerate revenue. Canada couldn't care less about the citizenship based taxation because of their deemed disposition tax
