Neo4j provides many benefits, but it has a few limitations as well, some of them are:-

The Neo4j database is not entirely open-source. Many functionalities are only available in the enterprise version.

It is very difficult to shard a densely connected graph in Neo4j.

Neo4j has an upper bound limit for the graph size which might be not enough for large graphs.

Neo4j does not have direct support for date data.

Learning and implementing Neo4j will take time as there are many new concepts that a user needs to learn.