Manufacturing costs and margins on LED-LCDs were far better for manufacturers and likely what killed Plasma.

Exploiting this aggressively helped Samsung win market share and become a top TV manufacturer, causing Panasonic and Pioneer to exit the business, and nearly kill off Sony. Their only real competition is on the low end with Vizio, HiSense, TCL, etc.

OLED still can’t match these margins, which is why only LG really makes them in large quantities. Others, including Samsung are dipping into OLED to capture the videophile market but not selling the sheer volume or making huge profits on them.