Govenment interventions with good data and track records

Does anyone have a good summary of interventions used by different countries, and the impact of those?

I have not travelled much, but so far the best, most affordable connectivity that I have experienced, has been in Taiwan. Is anyone familiar with the telecommunications history of Taiwan? There is Wi-Fi everywhere, but nobody needs to use it because the mobile networks are super fast and cheap literally everywhere. I know it’s a small country with a small population, and probably relatively cheap and easy to cover, but how did this happen and what were the factors? Are there other countries where similar dynamics have developed?