Not everyone is like that, but a lot of people are.
Not all Japanese are like that, but I think the majority are.
ーNot everyone is like that, but a lot of people are.
「みんながそうじゃないけど、たくさんの人はそうです。」
ここのthat は workaholic のことを指します。
ーNot all Japanese are like that, but I think the majority are.
「日本人全員がそうじゃないけど、大部分はそうです。」
majority で「大部分・大多数」
ご参考まで!