How easy is to pick an Uber from Iah?

I’m debating about what to do and thought you guys might help :).

I have family arriving at around 11pm today. I’m suppose to pick them up. They were suppose to arrive at 10 but their flight was delayed.

They are arriving at D. How easy and safe would be for them to grab an Uber? Or taxi? How available are at that time?

Or is it better to go pick them up my self ? If I go, should I ask them to move yo terminal B or access to D should be fine at that time ?