It is interesting to think that such a jam-packed movie could be a lonely shooting experience for anyone but I think that what Carrie Coon told Entertainment Weekly speaks to the nature of modern filmmaking, especially on a blockbuster.
That was the extent of her experience shooting Infinity War.
Carrie Coon only shot her motion-capture scenes for six hours in Atlanta before flying to San Francisco to get her face scanned at ILM.
So you can see how that could be a lonely, somewhat impersonal experience, just breezing in and not getting to act opposite anyone.