[tjohns]

This is a very good summary of the situation.

We have digital datalink weather, pilots love it and use it frequently. It would be nice to have D-ATIS at smaller airports, but otherwise weather is a solved problem.

For everything else, voice communications are a feature. Pilots are trained to spend most of their time heads-up looking out the window, not heads-down looking at computer screens. ATC via text message breaks that flow. (We do actually have ATC via text message, using CPDLC. It's most useful on oceanic flights as an alternative to HF radio, where things happen slowly. Once you're getting close to the destination and events speed up, it's back to voice.)

In theory the biggest benefit to CPDLC is uploading a clearance into an FMS automatically, which is already a thing... but even then you have to closely supervise and occasionally step in when it does it incorrectly.