it seems ridiculous to prosecute the particular crime of posession
what does this even mean? you mean with people hoarding CSAM shouldn't be charged because they're not distributing it?
Do people think there would be some dramatic explosion of CSAM?
Yes, this is not your local backwater town where you know there are a few visibly shitty & disgusting people and people tell their kids to stay away and everyone becomes safe. And if you think shit doesn't explode on the internet, you might be living under a rock last 2 decades.
That's stupid on a whole new level and your made up scenario doesn't make it any better. No one is threatened for having been sent some questionable content. The person who sent those however might be and the tech today makes it incredibly easy to prove where anything came from since everyone is being tracked.
Seize all funds received for distributing it, throw anyone involved in producing it in prison and throw away the key,
How about we prevent such things from happening by discouraging it in the firat place? Sure, they won't be down to 0, but your solution starting after the distribution has already started is highly disturbing.