That wouldn't be the first or last technology that made a debut and then dissapeared. In particular I remember reading a lot about software defined radio on all the tech websites back in highschool. Never had the money to buy it but I loved daydreaming about all the possibilities. Then it vanished. You couldn't buy the hardware anymore. No one made the software. No one talked about it.

Until 20 years later, then it suddenly reappears pretending to be a revolutuonary new invention. Except now everyone upgraded all their tech to be digital and encrypted.

However, quantum computing is a decoy. It can't logically work. And they never stop talking about it, making predictions, hyping up fake Qcomputers, and never delivering.

It's probabaly going to be used to explain away other tech the way Brits said carrots improve vision to explain away radar, and F1 guys pretended to have a new differential to explain away ground effect downforce.