How to send a mass text with no group?

If you send a group message to people who aren't using iMessage, then the message is sent as an MMS or SMS message.

All responses in a Group SMS are sent as individual text messages and the recipients can’t see the other responses from the group.

The only alternative to creating a group message is to copy the message and paste it into individual messages for each recipient. If you add more than one name as the addressee, then it becomes a group message.