I increasingly hear “invite” where “invitation” is required.

Problem:
The word “invite” is not a noun.

Explanation:
Sentences such as “I’ll send you an invite.” or “Could she send them an invite?” drive me crazy.

How lazy can one be?!

The word “invite” is a verb, not a noun.

We have a perfectly good noun for what is intended: “invitation”.

I believe that this growing tendency to use “invite” where “invitation” is required is consistent with my “Devolution toward Simpler” hypothesis.

It’s simpler to say or write the two-syllable “invite” than the four-syllable “invitation”.

Solution:
Use “invite” when you need a verb; use “invitation” when you need a noun.