In general, we talk about "iPad kids" and blame the tablets and phones themselves. Slightly more sophisticated people will blame the apps like YouTube or Roblox.
That stopped making sense to me once I saw the problem first hand with my peers and my own children. The actual issue is parents wanting to (basically) anesthetize their kids so the parents can do something as if they didn't have the kids.
Devices and Apps give parents the ability to zonk their kid into outer space for extended periods of time with unlimited videos or games that never end. But that isn't an inherent quality of the device. Like if you block all the apps and just let the kid use the iPad for drawing. Or if you do the YouTube kids thing where they can only watch videos you add to an allowlist.
The app makers do hold a lot of responsibility for the defaults on their apps, but the real issue is parents who are choosing to blackhole their kids for extended periods of time. (I am agreeing with you btw)