My ex-boyfriend always sends me that kind of mass holiday wishes on holidays. Why is this?

Sending blessings in groups is actually just a way for him to facilitate his work and life, and there is no other meaning.

Why do you say that? Because I often do it, because I live in a big family and have many relatives. When I grow up, in order to maintain the relationship, basically every family will add one or two relatives. Every holiday, I send messages to greet my elders and peers. It is impossible to send them one by one at this time, so I will send them one by one and choose to send them to everyone directly.

So I think your ex-boyfriend should do it for convenience, too. He has no other ideas. It doesn't matter to him whether he answers the letter or not. You are just a better friend than ordinary friends.