Well, they could destroy academia if the credentials start to mean something. There is no reason that a university is some special place to learn things. There are three things colleges seem to do fairly well - knowledge transfer, credentials that mean something, and research.

Knowledge transfer can happen online or anywhere if done right. Credentials that mean something is possible if there are reasonably good standards behind them that are provable. Say, some kind of standardized test/certification. Research could happen outside of the way Universities do it now.

For now those things are all tied together, but there is no intrinsic reason they have to be.