Microsoft's Azure Multi-Factor Authentication was an MFA solution acquired with PhoneFactor in 2012. From 2018 it is no longer available as a standalone product. This functionality is now provided by Microsoft Entra ID.
Honestly, they are very similar as is much of their offerings. It really comes down to which ecosystem are you already invested in? It doesn't make a lot of sense to try and interop with every cloud vendor - pick one and use them. While there used to be substantial differences …
If your solution falls within their standard use case or you have Office 365 - then it makes total sense. If you need a lot of customization or have a really specific business process that causes you to deviate from the standard flow it usually makes more sense to create a custom solution
Honestly, they are very similar as is much of their offerings. It really comes down to which ecosystem are you already invested in? It doesn't make a lot of sense to try and interop with every cloud vendor - pick one and use them. While there used to be substantial differences in the cloud platforms, they are at basic parity now