I’m not sure if they’re a fad. There is definitely a fan base for them. Not for me but others do like them
I love autographs and will always collect them. 2022-3 really evolved how I collect however. When I started collecting signed Pokemon cards in 2019 I chased something from every artist, now I moreso dont have that spark for anything I personally didnt get signed myself. Regional artist events have taught me I value time spent meeting the artists more than the items themselves.
With all that said no I do not believe its a fad at all, we were spoiled last season by access to artists stateside and that really electrified what was up until that point still kind of a niche side of the hobby, for better or worse.
There will be two peaks. One when the artist stops doing autos and the second when they pass away.
There may be a third if Pokemon gives in to the AI fad and people try to grab some of their favourites. But I can’t see Pokemon doing that for a long time, possibly ever. At least I hope not.
Its possible the money-mayhem train may eventually do what they do and move from autos to smth else, but I think collectors seem very interested in autos. Speaking personally, my autographed cards are some of the most invaluable, coveted items in my collection. Getting to attend a Pokemon event, meeting other collectors, seeing the artist in person; signings are incredibly special to me as a collector. The whole experience is great. I know many others feel similarly so i dont think autos are going anywhere!
Personally I dont think artist autos are a fad in Pokemon.
Slightly off topic here, but I also want to express that I am grateful in how collecting autos had helped to shift my preference away from prioritising conditional rarity. Take the 1996 charizard base japanese for example; I own a psa 10 for years that ive self graded and always felt that it was much superior than a 9. However after obtaining a psa 9 arita sketch zard from the paris event last year, I found the appeal to holding onto the 10 to be much lesser now, as I own a copy that prolly have 1 or 2 more specks of whitening, but much more flair and a story to it.
As the attachment to psa 10s had slowly crept away, I am likely going to sell my psa 10 and purchase something like a psa 9 goldstar japanese rayquaza, something in which a psa 10 would have been out of my budget.
Happy collecting guys!