Bitcoin is still illegal in our country so it is impossible to buy Bitcoin through bank transfer, debit card or credit card in this country. So most of the people who buy bitcoins for investment here buy through P2P. Although Cex is not safe for us, we can buy bitcoins through these exchanges.
If they don't know you use bank transfers for purchasing bitcoin and cryptocurrency, you will not have any problem with banks and your bank accounts. There are ways to do Bitcoin trade without informing banks that you make bank transfers for cryptocurrency related trades.
Peer to Peer trading is one of ways to do this in nations with Illegal status for bitcoin and cryptocurrency. The Legality Map shrinks with less and less nations with Illegal status because Bitcoin adoption is increasing.
https://newhedge.io/terminal/bitcoin/legality-maphttps://coin.dance/poli/legality