I too, have noticed more appendix carry in gun videos I watch. I don't know if it's the cool kids, or what.
FWIW, I have yet to find a kydex (vs hybrid) holster that is comfortable for me for IWB. I have several, and can tolerate them, but they just come nowhere near leather for long term comfort. Hybrids are a little more tolerable than 100% kydex.
I'm mostly only doing IWB with small guns when I have to be IWB, like going to Costco or similar where "concealed means concealed". Otherwise I'm all OWB. Just a great advantage for me for both comfort, and more importantly, fast firearm access.
EDIT: For clarity, the leather vs kydex comfort issue for me is IWB. For OWB, I'm currently mostly using full kydex, with the exception of the Milt Sparks 55BN that I use for the 1911. There's no doubt (from my experience only) that I can get a faster draw out of the kydex OWB than the leather OWB. The 55BN is really good in that regard for leather, but still not as fast as full kydex.