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?
Philippines is one of them they allow people to buy Cryptocurrency though indirectly, they will have to deposit funds to their coins.ph account this is a local exchange, using bank that are their partners after you deposit you can buy Cryptocurrency and you can also sell your Cryptocurrency and withdraw it using your favorite local bank.