Why Can't I send pictures to or be in group chats with people who don't have iPhones?

Why Can't I send pictures to or be in group chats with people who don't have iPhones?

That depends on a lot of factors. I don't even know what messaging app you're using. But it sounds like you need to find an app that is cross-compatible, meaning you need an app that iPhones and Androids can share, like Facebook Messenger, Instagram, Snapchat, Kik, etc.

There are apps that it is available but everyone would have to have that app. WhatsApp as an example.