I would recommend these two countries Indonesia or Thailand for
Internet
Food
Cost of living
Transportation
Best nature and environment always
Easy to obtain citizenship
Bali don't have tax on personal income
Thailand have 5% tax slab on income
If you just focusing on tax then got for gulf or carabian country are best but other things are fit in your criteria especially citizenship which you don't get,
You can't get an affordable life in these countries
because one hand they asking no tax on other hand for like internet, house, food, and transactions, expenses like hell.