Answering your second question first, Data Centers are not more secure than the Cloud Platform.
Cloud Platform uses methods like VPC, IAM User, Role Creation etc for providing enhanced security. You can read more about security provided by Cloud Platform in this documentation by Amazon.
The first question, there are soo many benefits in migrating your business to cloud platform. The major benefits can be as follows:-
- Disaster Recovery
- Enhanced Cost Management
You can find more benefits here in this article. Hope you got answers to your query.