is there a way to block players based on country.

If you abort too often, as a percentage of recently completed games, you lose the ability to abort and all games that start as rated will be rated.
https://support.chess.com/en/articles/8598007-what-is-chess-com-s-sportsmanship-policy

Stop asking for this feature. They are not going to cater to your confirmation bias.

Turn on focus/zen mode and you won't have to deal with seeing a player's country, nor the chat until after the match is over! You can choose who to play against by looking through the "open challenges" tab on the play screen, if you really want to cherry pick your opponents. Don't see the problem with playing ppl from other countries though, because this is an international site.