Did you drop a sarcasm tag? Anyone can make a fire on a plane as they allow lighters on a plane, and batteries, and any number of flammable objects. None of that is facing any scrutiny nor stopping crazy people from being crazy.
I take security that catches 50 or even 20% of threats any day over 0 security.
My checked luggage did not pass xray multiple times because they detected powerbanks. I had to come back and take it out. However it also did pass xray a couple times with powerbanks so it's not a reliable system.
But you can still have multiple batteries (I think up to 10 or so) as long as each individual one is less than 100Wh.