No one disagrees that fully autonomous vehicles have great potential. But for now they’re a huge money pit, and estimates for when they will come to market keep getting pushed further and further into the future.

The latest estimate is that the autonomous vehicle industry will not develop a fully autonomous car until 2035, according to research firm GlobalData. It’s certainly not for lack of trying. According to McKinsey & Co., investors have poured about $100 billion into the sector, with more than 1,000 companies snagging funding.