>Remember the Snapchat Spectacles? They still sell them but I don't think they were ever popular. Google glass? Popular, but discontinued. Apple's ARKit? Definitely much less adoption than their commercials would have led you to expect.

This is all pretty inaccurate. Glass wasn't even a VR/AR headset. The released Spectacles were just cameras. They're releasing a new Spectacles devkit that's actually an AR headset soon. Snap filters are still very popular and ARKit is also quite popular although it hasn't really hit a killer business case.