Foreigners are not fully exposed to the local market though, so there's no need to do capital controls. _Income_ is never an issue, as there are taxes to cover that. The main thing being cracked down on is people moving accumulated _wealth_ out.
Also, things have changed _considerably_ since 2016 (as these things tend to do). Indeed, nobody --- foreign or domestic --- needed to document use as long as you stayed within the $50k (you would be asked to if you went above that). Later it became a mandatory question, but wasn't enforced. These days it is enforced rather strictly. If you claim education, you need to provide statements of tuition and housing etc. For tourism there's similar requirements, and usually they limit discretionary spending budgets to ~$10k.
Also, things have changed _considerably_ since 2016 (as these things tend to do). Indeed, nobody --- foreign or domestic --- needed to document use as long as you stayed within the $50k (you would be asked to if you went above that). Later it became a mandatory question, but wasn't enforced. These days it is enforced rather strictly. If you claim education, you need to provide statements of tuition and housing etc. For tourism there's similar requirements, and usually they limit discretionary spending budgets to ~$10k.