Banks in Germany started to allow people to buy and sell cryptocurrencies this January 2020. I think other countries will do the same soon, Japan might be another country with such services. In the beginning, someone has to start something so others can follow suit.
What are the other countries where anyone legally can buy/sell cryptos at commercial centralized banks?
Wow that's really cool tho, i can't really imagine that there are some countries that can allow to buy and sell crypto currency in their bank, that really awesome i hope my country will allow it too. But do you think that government itself who allow it?
on what country you reside ? if your government blocked cryptos then chances are you cant use cryptos too as well as those services mentioned here will not also be possible but dont worry because your country will not be forever like that . many countries are now crypto friendly and soon no countries will be left out because that will be shameful for them if they will act differently . however if cryptos are already legal on your place but there isnt a service like this , you are still always welcome to buy and sell on other platforms . there many of them .