How much do you trust the Microsoft E5 Security stack?

Considering ditching a lot of third party tools and going all in with Microsoft by upgrading from E3 to E5. My Director is very keen for this due to the cost savings but I have reservations of relying just on MS despite all the investments and Gartner reviews. Has anyone else been through this and how did it go?

cost cost savings cybersecurity director gartner microsoft party reviews security stack third tools trust