If you think the Phuket Sandbox is a shambles, consider the recent experience of Spain:
Tourism hotspot Spain's grand reopening to international travel got off to a slow start on Monday, with newly relaxed entry requirements failing to attract the desired wave of foreign visitors amid confusion over the new rules.

Hoping to revive its struggling tourist sector Spain began letting in fully-vaccinated people from all over the world on Monday, but only published detailed rules on Saturday, leaving travel operators and tourists in the dark until the last minute.
https://www.reuters.com/world/europe...at-2021-06-07/