Using avocado oil as a substitute to olive oil
See What oil or fat to use for different purposes? for a general discussion about choosing oils.

If you are using unrefined avocado oil, you it will have a unique flavor that will affect your dish or outcome, and in that case, the flavor would be the primary purpose.

If you are using refined avocado oil, its main unique characteristic is that it has an unusually high smoke point at about 480 F (250 C).  While this may make it exceptionally suitable for applications like deep frying, you would have to consider whether the cost is justified, given that many more available and lower cost oils (at least in much of the world) perform very well, and most deep frying temperatures don't exceed 375 F (190 C).

As to a drawback&mdash;if you exclude cost&mdash;no, there is no reason to avoid refined avocado oil in recipes.