I largely agree, but I do think it's worth noting that they do actually have a screen sharing feature.

I don't use the screen sharing feature, and have no desire to use it, so it is quite irritating that they require the subscription to automatically sync my under a megabyte documents on the occasion that I need that.

Fortunately, it does still have Google drive integration which does not require a subscription. It does require a bit of manual work, but it's not bad

Does screen sharing go through their cloud service or is that a local device-to-device system, similar to AirPlay?