Nest cams are definitely more expensive and the quality is not as high; the only reason to get them instead of a trail cam is if you can't/won't fetch the SD card from the trail cam (or you really want a surveillance cam for that area that you can look at anytime from anywhere). I don't actually really highly recommend the Nest cams for wildlife videography as the quality isn't super great. I just happen to need the ability to access them remotely and I use them to watch my front and back doors as well.
And also to get alerted when there's a cat trying to prey on the birds at my pond so I can turn on my sprinklers bwahaha.
