It took decades because people couldn't afford computers, nor could they manufacture at today's modem scale, that's what took long.

In terms of adaptation, once someone had access to a computer, with few exception people found some utility in their daily lives for it.

IMHO, folks who have access to crypto are not finding any immediate use for it in their daily lives. And further, it doesn't seem to scale very well. Sure, enough coins exist, but they can't be transacted without massive fees. Ergo, doesn't scale currently.

If some breakthrough solves the scaling problem while retaining it's decentralized nature, it may gain some utility.