I started with the "progenitor" at least in mainstream and more broad and general terms, with the one, the only, Kizuna A.I. I guess you could argue that PNG Vtubers/people using avatars and voice softwares (mainly good ol' LOQUENDO), was my gateway to almost very similar but not quite close, to Virtual YouTuber-like content. I was weary of the idea of using 3D avatars, and live2D ones, but that was more so back around in like 2007... 2009/2010 or so.
I ended up getting invested in Holo and other proper Virtual YouTubers, I guess the one that got me hooked into the company was a mix of Korone, bits and pieces of clips of Pekora, as well as the dragon president herself, Coco, and when I was somewhat watching Niji (before the whole mess) if I'm being honest, the one that got me hooked into it was, one of the OG good chads left in that shithole in Rosemi, mainly because she was one of the very few ones that played Yu-Gi-Oh! (mainly Master Duel) here and there. Good times