Hiya, creator of almost a thousand of the fonts we have in the All Fonts Pack. I just want to provide my own full honest take.
I've been making fonts since 2005. Yes, I've made that many; I've been making them near full-time (alongside games) since 2015, with over 200 fonts before then purely during off time from my full-time job.
I've absolutely dabbled with AI before, mostly in its early days. It doesn't work for fonts - any amount of effort spent fixing it was more than just making fonts myself from scratch. I was probably on 800 fonts made already at that point; I have a very optimised way of making fonts in the styles I have expertise with, hence the speed. I can make a font in 2 hours if it's fairly geometrically simple and I'm already set on its style leading into it. Every font I've made since 2005 has been made in High-Logic Font Creator, FontStruct, or (in about 5 cases) scanned in with my own handwriting.
I have used AI in a video game - once. A free game I made called Typing Your Bass used 2022 DALL-E. It was fun to play with at the time, but I've never used it since.
As for thumbnails: Spirit Fox's might be AI. I source my font thumbnails from a handful of free stock photography websites, since their only job is to provide a quick fitting backdrop for the font I'm releasing. (This is something I have had to do for every single font I've made, it is time-unviable for me to create the art). I do not use AI for this - I prefer the look of generic stock photography - but those sites may allow AI. In Spirit Fox's case I just went for a magical-looking fox. That's it - it was a 20 second decision on a website after finishing the font and getting it ready to go public. More than happy to replace it for future use.
My *personal* stance is that AI has its valid applications. I'm not against those. But I'm against using it myself, and proud of what I've made without it. That's a motif we both share as Chequered Ink.