I was looking for this comment.

Creating a group chat with everyone invited is a terrible idea because of the snowball effect of the first "Sorry, can't come, but have a good time for me!" message triggering a neverending stream of similar cancellations until sometimes the entire event ends up cancelled on the day of.

People are way less flaky if you invite them 1-on-1 (even if you copy/pasted the invitation message) vs. a group chat.