There is definitely a problem when it comes to the general public taking warnings seriously. Flash Flood warnings are rather common compared to other types of weather events, but they don't get the attention they probably deserve, unlike tornados. And to be honest, much of the public has a disdain for meteorologists because of the perception they aren't accurate, which isn't really true, or because they've been brainwashed to think the NWS is just wasteful spending. So as much as I want to care about people, I can't bring myself to do so when there is so much willful ignorance out there.
In the case of the Texas floods, the NWS issued flash flood warnings and flash flood emergencies before the storms hit. The main issue is that the storms happened between 1 and 4am when everyone was asleep. Apparently, Camp Mystic has a "no phones" policy as they are a Christian summer camp, so presumably nobody received the flash flood emergency push notifications which did get pushed. From a mesoscale perspective, this was basically a perfect situation where the remnants of a tropical cyclone drove enough moisture into a stalled out front over Texas, which allowed the storms to train over the same area, squeezing out incredible amounts of moisture, 10+ inches in a few hours.
There's no doubt in my mind that these sort of events are becoming more common, probably for a few reasons.