There's a whole lot going on with paint. Paint inflation started about 2 decades ago with the increasing VOC regulations. I watched paint go from a typical $15, to $25 quickly (during zero inflation time), and drifting up from there, until this recent shock.
Paint is now a high tech material. We've come a long way from linseed oil mixed with some ground up clay, lead or berries. Now it is a carefully engineered material that is essentially quick curing plastic.
As someone mentioned above, this highly engineered material has many components distilled from petroleum. We had the whole "resin shortage" after the Texas cold wave. Add base oil prices to it and it gets worse.
But there's more. The housing reno fad of the pandemic, along with flippers everywhere, increase demand. Flippers paint everything. I swear they'll even paint your dog.