BUT.. I think they are leading to a loss of critical blood trailing skills in hunters. Over the past 5 years or so I continue to see threads posted across the internet where people seem to put forth a lackluster tracking effort and the responses are "just call a dog".
There are always people uninterested in learning a skill for various reasons. There have always been hunters who can't/won't learn to bloodtrail their own deer. Historically since they couldn't "call the dog" they "phoned a friend." Or looked for 10 minutes and shrugged it off. Dogs won't change that baseline level of incompetent folks.
Trackers usually don't work for free. Down here it'll cost you $100 or more to get somebody who should know what they're doing to come out. That dissuades a lot of people from relying on that as a go-to option. You MAY get somebody to come out and do it for free or for "gas and dog food", but you're most likely getting somebody like myself who is trying to teach a dog...not exactly an easy-button. Prices go up from what I understand in areas where deer get bigger and wallets get thicker. And there's no guarantee the number you call will pick up. A good tracker stays busy, and generally will be reluctant to bring a dog out on a trail he doesn't think has a dead deer at the end of it. If you talk to him and can't give him confident answers to his questions (Where did you hit? How did it react? What does the arrow look like? Do you have blood? What did it look like? Did you follow it? etc) his interest drops. Amateurs like myself kinda lose interest when people call at 8pm on a Sunday night...
There just aren't enough trackers out there to make "call the dog" anybody's first thought. And even if you have a dog who can follow trails (mine shows promise) going back to the house, loading him up, and fooling with him is enough hassle that you'll probably make at least an attempt to follow the trail.
I don't doubt that you've noticed more people interested in dogs or advising folks to use them. It's trendy currently (like "mobile hunting"), and "call the dog" is also a polite way to tell somebody who obviously doesn't have a clue to stop asking the facebook for advice and go fix their problem. It's hunting's version of "drain the gas, replace the sparkplug, and clean the carb" as a default reply for the ole "Why won't my engine run" question on go-kart forums. Hard to diagnose an engine or blood track a deer through the internet. "Call the dog!" is also used as an in-joke by the crusty-ole-bass-turds around my area to poke fun at the guys who post pics to instagram in their Sitka suit after gut-shooting basket racked "public land trophies" with 6.5 creedmoors out of their saddles...
But there just aren't enough dogs and trackers out there to affect the number of people who will be too lazy/ignorant to find a deer. Even if there were, folks hate paying for a service. They'll buy a GPS or camera or replaceable blade, but ask for money in exchange for years of training a dog and working trails yourself (not to mention the cost of buying the gremlin, feeding him, taking him out to crap, scooping said crap, taking him to the vet when the crap looks funny, having him crap in agreed-upon no-crap zones, etc, etc) and they get cheap.
If what you're saying was true, it'd be a whole separate thought altogether whether matters or not. You don't see people crying about kids these days not being able to tan and sew their own buckskins or shoe their mules or smoke their venison hams so they don't rot... Sometimes skills and tools become obsolete. And I say that as a guy who likes to think he's better than the average bear at killing and finding deer.