I haven't been using mine as much as I'd like to but I think that's more because I mainly only photograph family etc so I lean more to actually enjoying myself rather than being distracted trying to get good photos. The size and weight has also come into play a little with things such as going to Center Parcs and worrying about lugging it around. A Sony A9 with a discreet prime would be easier, but again for family shots I can't justify the price.
Annoying, whenever I do get the D750 out the AF and image quality make me kick myself for not getting it out more often, phone camera shots just don't cut it for me. I think I need to find a decent but not oversized rucksack which can swallow up and protect the camera and lens and also double up for carrying other stuff.