For us. the container was a better solution then what Intune provided. Ease of Management was probably the biggest reason. For IOS, users would use the Outlook app for their personal email as well as the companies. We couldn't lock down the app well enough without taking complete ownership of the app, which meant they couldn't have another email setup within the app due to our policies.
We tried Intune, even brought in a company to secure everything but Security kept finding holes they didn't like.
I also used Jamf for some things, Intune for others, it was all over the place. Glad that WS1 was able to manage everything they way we need it to.