M365 (the business plans) are an insane value, with zero competition. Remote management of devices, zero-touch provisioning of new hardware, full security suite, etc.

There's nothing OSS or commercial that even comes close, especially for the price.

I'm sure the average small business doesn't even use half of the functionality, but it's all there when they want to get serious about security/administration, or it can be outsourced to turnkey MSPs.