To get closer to calculating the ROI that Microsoft 365 brings to your business, you need to be familiar with how the subscription licensing works. With many Microsoft product areas having monthly update cycles, this means that features can either be added or can drift in and out of existing SKUs.
If most of your users have the same role, but you have more than 5 different license types active in your tenant, chances are there's room for some value add.
M365 licensing has always been one of my strong points, having run an MSP myself and worked on some larger deals over the past few years.
