So many different perspectives. . . so many different opinions.
Economics: In some cases engraving can add a lot of value to a knife. Just as often, especially once we venture beyond bank scroll and gold applique flowers or leaves and get into specific subjects like animals, people, etc. , , , you are definitely limiting your future market - even if the execution of the engraving is excellent. Someone is going to have to like the subject of that engraving to buy that knife. Kind of reminds of of the way realtors always want you to paint the walls in neutral colors, etc., when you are preparing to sell a house. The very personally appealing things about a house or a knife that are reasons you like it so much may be the biggest problems when trying to sell unless you get lucky and find a buyer who shares your exact particular tastes. So anyone buying or commissioning an engraved knife with a specific them or subject matter should walk into it with their eyes wide open and hope that they really love it because there is no guarantee that anyone else will, no matter how talented the engraver may be.
Aesthetics: In general, I consider very few knifemakers to be outstanding engravers. Personally, I would not ask Firmo Fracassi, Winston Churchill, Brian Hochstrat, Torcoli, etc. to make a Damascus Bowie or a slipjoint. Likewise, I generally believe that the vast majority of knifemakers would be better to avoid engraving. There are a couple of exceptions - but that is about it, and IMO a lot fewer than other posters here seem to think. IMO, there is too much praise here for mediocre (and worse) engraving. I wonder how much time some folks have spent examining engraving by top masters before forming and expressing these opinions. The Engraver's Cafe is a good resource. Spend some time looking through some books on engraving. A friend turned me onto a book by Roger Bleile: "American Engravers - The 21st Century" which my wife bought me for Christmas. Amazing stuff! Spend some time examining the work of the best masters, and then objectively ask yourself if what you see most knifemakers doing which you see so much praise heaped upon here is really in the same league as work of these engravers. If a knifemaker is going to engrave a knife, IMO generally best to keep it as simple as possible.
I have seen more than one expensive knife ruined by "adding" a couple of thousands of dollars in engraving. The consistency of too many well-known engravers is lacking. Sometimes it is excellent; sometimes it is . . . not. I will not call out anyone, but just within the past few weeks I saw a knife posted up here which was engraved by a very well known and prolific maker who IMO generally does a fine job. Extreme close up pictures were not kind in this case. I was surprised - and not in a good way.
I own several engraved knives from a variety of different engravers. Most also have gold inlay, which I like. I have some others in planning stages. Many I commissioned myself. Some others I bought already engraved. I have had many of these knives for years with no intention to sell them, so they really do only have to appeal to me. There are things I like and things I do not like, but that is all just subjective personal taste, so I do not see a lot of value in discussing them here.
Is this a "golden age" for knife engraving? I don't know - I think only the perspective of time can allow one to answer that, some years in the future. But I have examined quite a few knives engraved several years and even decades ago. In general I believe that the work that is being done today is much better than in the past. The same can be said for the application and working of gold, jewels, etc., and other artistic flourishes. I have seen some famous and very expensive "art knives" from decades past, and as remarkable as they were in their time . . . in some cases they really do not hold up at all to the standards of what folks are doing today IMO. Maybe in another 20 years, I would say the same things about the works of today.